(CNN) -- Colleen O'Bara bathed her older sister, Edwarda, and fixed her hair. She fed her through a feeding tube like she'd done countless times. It was going to be a good day, the day before Thanksgiving.
With her morning routine complete, Colleen planned to fetch a cup of coffee. She bent down and kissed her big sister, told her she'd be right back.
"She gave me the biggest smile she has ever given me in her life," Colleen recalls. "Her face was aglow. There was a sparkle in her eyes."
But just then, Edwarda closed her eyes.
For 42 years, her family held vigil. They awaited the day Edwarda would awake, the miracle that never came.
At the age of 59, Edwarda died, believed by medical experts to have lived longer than anyone in a comatose state.
Her father, Joe, died six years after she fell into her diabetic coma, the strain of working three jobs to pay her medical bills too much. Her mother, Kathryn, had promised to never leave her side; she died in 2008 after caring for Edwarda for 38 years.
Former President Bill Clinton, Florida Gov. Jeb Bush, singer Neil Diamond and other celebrities visited the home over the years. Renowned self-help author Wayne Dyer penned a book, "A Promise Is A Promise," about Kathryn's unconditional love.
Thousands of people -- from Japan to Australia, from Italy to Canada -- took the pilgrimage to the O'Bara home, inspired by the devotion of her mother. They were drawn too because they believed Edwarda had miracle healing powers: A woman with an inoperable brain tumor was cancer-free months after she touched Edwarda. Two girls with cystic fibrosis were apparently healed in the months after visiting her room. Even skeptics said they felt a strange aura when they walked into the North Miami home.
Kathryn claimed Mother Mary appeared in visions. Mom wrote Pope John Paul II. He responded with letters of his own.
On the walls of Edwarda's room, Mom pinned inspirational quotes: "Where there is great love, there are great miracles."
The Hemlock Society phoned often, pleading with the mother to let her daughter die. The day after Christmas in 1981, someone called to say he was going to put Edwarda out of her misery. A few hours later, three bullets were fired into the home. No one was hurt.
Edwarda was just 16 when she fell into her comatose state. Her favorite song then was "Bobby's Girl," because she had a crush on a boy named Bobby.
In the decades that followed, Bobby would visit the home, but she even outlived him.
It seemed Edwarda touched everyone she came into contact with, even the doctor who saved her life. He struggled with the ethics of what he'd done.
He wondered: Would it have been better if I'd let her die?
A promise kept
Edwarda and Colleen were inseparable, born just 18 months apart. Edwarda was the studious, obedient, loving child. Colleen was the mischievous tomboy.
"She kept me in check," Colleen recalls. "I had a short fuse on my temper when we were younger. My sister was just calm. She put up with me unbelievably."
Family photos show the bonds of sisterhood at an early age: as ballerinas, on Santa's lap, playing with the family's German shepherd. Birthdays, Thanksgiving and Christmas were a bundle of fun, a time to celebrate as family.
"All I ever wanted in life was to have two girls. God was very good and granted me my wish," Kathryn O'Bara told Dyer in his book.
Kathryn McCloskey and Joe O'Bara married in 1948, a promising young couple eager to start a family. She was the daughter of the mayor of Johnstown, Pennsylvania. He was the Navy's middleweight boxing champion during World War II and went on to star on the University of Pittsburgh's football team.
The family eventually settled in South Florida. Joe became a physical education teacher at a Catholic elementary school. Kathryn -- Kaye to family -- taught math at a high school.
Kathryn's niece, Pam Burdgick, remembers her aunt and uncle as pillars of the family. She went to college in the mid-1960s in South Florida and would stay with the O'Baras on weekends. "Kaye was the personification of unconditional love. That was for all of us, not just Edwarda."
Edwarda, then 12, would watch her put makeup on. "She was a sweet, loving child."
Like so many girls, Edwarda and Colleen loved horses. At a nearby ranch, the sisters' friendship grew. "Colleen had horses, and Edwarda had a pony because she was always the cautious one," says Burdgick.
Edwarda did the hard work around the stables, allowing her younger sister a lot more time to ride the horses. "My sister would clean the stalls, brush the horses, let me have all the fun, and she would do all the work."
"That's what she wanted to do for me. She's the most giving sister that anybody could possibly have had," Colleen recalls. "She was my best friend in the whole wide world."
Edwarda was diagnosed with diabetes in late 1969. She was prescribed an oral insulin medication -- a medicine that is no longer given to adolescents due to harmful side effects.
Her diabetes didn't hinder her studies. A junior in high school, she got straight A's. Edwarda had been accepted to the University of Notre Dame, at a time when the school was mostly male. She hoped to become a pediatrician.
The family looked forward to Christmas that year. But during the break, Edwarda fell ill with the flu.
"She was sick and throwing up and stuff," Colleen says.
If Edwarda had been given insulin shots, her bad bout with the flu likely would have been just that, nothing more. But every time she vomited, she was throwing up her medicine -- and sugar was building up in her system.
By the time anyone realized what was happening, her health had deteriorated.
Joe O'Bara had just returned from a fishing outing when he went into his daughter's room. The skin on her legs had sugar lumps under them, like Charley horses. They were all over.
"My sister was screaming. I remember it like it was yesterday," Colleen says. "My dad started rubbing her legs to try to get the sugar to flow in her legs. He picked her up, and we just rushed her to the hospital."
It was January 3, 1970, when Edwarda arrived at North Miami General Hospital around 2 a.m. -- Joe and Kaye's 22nd wedding anniversary.
Dr. Louis Chaykin, who was on call that night to treat another patient, remembers seeing Edwarda and her mother in the emergency room. Daughter and mother were holding hands.
"I remember the words the daughter told the mother when she was lying in the emergency room: 'Don't ever leave me,'" the doctor says. "And the mother said she never would."
Soon, her lungs collapsed. Her kidneys failed. Her heart faltered, causing a lack of oxygen to the brain.
Chaykin was 35 then. A nurse suggested Edwarda's mother ask him to care for her daughter. He was an endocrinologist with specialized skills.
"When I saw her, she was almost near death. It was a Sunday. We worked on her for hours," he says. "We got her into intensive care, and we were able to reverse a lot of the metabolic abnormalities, but the damage that was done to the brain appeared to be permanent.
"She was in a comatose state. She would respond to pain, but that was it."
Colleen, then 15, continued her life at school, thinking her sister would eventually be OK. "I didn't realize how bad it really was," she recalls. "You see, my sister wasn't on any machines or anything. She just didn't wake up and speak."
For five months, Edwarda was treated at the hospital. The family refused to put her in a nursing home. Medicaid would have paid for those expenses, but mom had made a promise. And so they brought Edwarda home.
"To my parents, if you promised somebody something," Colleen says, "you never broke a promise."
The parents' bedroom in the family's humble bungalow was transformed into a round-the-clock care center, with Kathryn serving as chief nurse. She set up a folding chair next to Edwarda's bed. It was eventually replaced with a brown velvet recliner. Every two hours, she fed her daughter baby formula through her feeding tube. She had more than a dozen alarm clocks. They went off at midnight, 2, 4, 6 in the morning. Angel figurines and family photos adorned the room.
Mom gave insulin shots, turned her daughter so bedsores wouldn't grow, changed her diaper. Mom's back grew hunched from slouching over. She got arthritis. Sleep came in 75-minute power naps.
Chaykin pledged to treat Edwarda for free. He set up an IV for fluids and the feeding tube through her stomach.
"It's not a big deal," says Chaykin, 77. "Recognizing the cost of just maintaining Edwarda, it was a non-starter. I wouldn't accept any money."
Kathryn called the doctor her angel.
Yet, as he watched the family grapple with Edwarda's condition and her father die under the weight of it all, the doctor worried that he might've done the wrong thing by saving her.
"I felt that it was very futile," Chaykin says. "That was early on."
His views, though, changed with time. "I became so impressed by the dedication and the love that this mother had. As I grew older, I thought that, perhaps, God had a better reason for me allowing Edwarda to survive, albeit in a comatose state."
He remembers watching hundreds, if not thousands, of people visit Edwarda's bedside because they believed "there were certain miracles that would happen if they came and visited Edwarda and touched her."
"There were different things that happened that I could not explain as a doctor," he says.
He wondered: Was it coincidence or something more?
'A mystery of faith'
No one remembers exactly when the first of the perceived miracles happened. Most everyone from those early days has died. But whatever the cause -- a mother's devotion, visions of Mother Mary -- word spread, and people ranging from sick children to missionaries on healing trips flocked to the home.
Joi Mejia brought both of her young daughters, around 6 and 8 years old, to the home. They suffered from cystic fibrosis.
"I was willing to do anything and try anything," she says.
Kathryn O'Bara had been Mejia's kindergarten teacher. She had heard of Edwarda's healing powers and felt the urge to visit -- the start of a friendship that lasted until Kathryn died.
"The feeling of peace and love in the room was so profound," she says.
In the months that followed, doctors told Mejia her daughters no longer suffered from cystic fibrosis, something the mother chalks up to the miracle of Edwarda. Touched by what happened, Mejia helped Kathryn tend to Edwarda for years.
"There were many miracles that came," Mejia says. "We don't always get a perfect package, but we always get a perfect soul."
A woman from South America once visited. Chaykin said she'd been diagnosed with an inoperable brain tumor, traveled to Massachusetts for a second opinion and stopped at the O'Baras' while flying back home. She prayed at Edwarda's bedside.
"About six or nine months later, a truck pulled up with new furniture for the whole downstairs with a note saying, 'I just got back from my doctor, and the tumor I had is gone,'" Chaykin says.
"Those things happened all the time."
Adds Mejia, "That was the freaky part. People came from everywhere. Why would it draw them? ... It's a mystery of faith."
A devout Catholic, Kathryn told people that caring for her daughter was a blessing from God.
Yet she could also muster a joke about its physical toll. "If I could turn myself in and get some new parts, I'd be all right," she once told the Miami News.
The family fell into mountains of debt. Joe began painting homes and fixing motor boat engines for extra cash to supplement his teaching income. But the pain -- both financial and emotional -- was too much for the Navy tough guy, who died in 1976.
"No question that it contributed to the father's death," says Chaykin.
Colleen gave up her dream of college to help her family pay their debts.
Already shattered by her sister's condition, Colleen's pain deepened with the death of her father.
She wondered: What type of cruel God would torture a family so?
The power of two words
Mom never lost faith.
She rarely left her daughter's side, let alone the house. On Mother's Day in 1982, Kathryn had a heart attack as she watched Edwarda sleep. She was hospitalized for 10 days, the first time she'd been away from Edwarda overnight in 12 years of caring for her.
Among those who covered the story was Miami Herald columnist Charles Whited. He first met the family in the years after she fell into the coma. He'd write a column around the holidays of a mother who refused to give up on her daughter.
"I've seen her, over these years, alternately buoyed by hope and crushed by despair, with even her faith tested as she awaits the miracle that never comes: Edwarda's awakening," Whited wrote in 1982.
Kathryn would call him often. Sometimes, she'd send letters. Her return address always carried the message: "Hope never dies."
"One of these days Edwarda is just not going to be able to fight off another infection," she said in one of her letters. "But even then, I will be richer for having cared for her and experienced all the love that people have shown her."
The next year Whited penned a different column. In August of 1983, Edwarda's mother said she'd heard her daughter utter one word: "Hey." She was in the kitchen with friends at the time. They rushed into the room.
"You'll never know the sensations that went over me. It was Edwarda's voice. We all ran in. She was smiling, as if she had done something terrific," Kathryn told him.
The next night, Edwarda said "hey" again. Kathryn wept at her bedside for an hour.
Whited asked, what if Edwarda never said anything again.
"I'm so elated that nothing can knock me down now," she told him. "Edwarda spoke. She really spoke."
Edwarda would never speak again. She would outlive the columnist. By 21 years.
The years came and went. Mom remained steadfast, always hoping, always praying. Edwarda had been reading the James Michener novel "Hawaii" when she fell ill during that Christmas in 1969. Mom read it to her more than 10 times over the years.
"It was never a sad place," recalls niece Pam Burdgick. "She always considered it a privilege. She loved having people come and visit. ... You left with a kind of sense of priorities, of how important family is."
While pilgrims made their way to visit Edwarda in South Florida, across the state a very different saga was playing out: that of Terri Schiavo, whose persistent vegetative state became a political, legal and family feud with her husband wanting to let her die and her parents wanting to let her live.
Schiavo, 41, died in 2005 after 15 years in a coma after a judge sided with her husband.
Kathryn paid attention to that battle but didn't cast judgment. She told people that families must deal with such tragedies in their own way -- and hers was united behind Edwarda.
Stephen Mayer, a professor of neurology and neurological surgery at Columbia University, has treated many comatose patients over the years. He says new research suggests that patients in persistent vegetative states may perceive what's around them in a way that doctors didn't previously understand.
"The best evidence of that are people who don't follow commands and appear to be vegetative, but after several years they wake up and start following commands," says Mayer.
Mayer, who did not treat Edwarda, says it's possible "she was perceiving what was going on around her to some extent over those 40 years, but not really able to communicate to us in a way that we can believe. And maybe the daily contact, the voices, the touches with her loved ones gave her reason to live."
"One thing I've learned over the years as somebody who treats people in a coma and tries to save them," he says, "is there's something very important about human contact with the people that bring meaning to your life, your loved ones."
Kathryn believed that to the fullest.
"God has given me the strength to care for Edwarda by sending angels in many forms -- friends, families, strangers who became friends, and many others," she told Wayne Dyer. "God has given me the gift of staying cheerful and being able to help others."
In March 2008, at the age of 80, Kaythryn was found dead on the floor in her daughter's room. She'd cared for Edwarda for nearly four decades. Mom had kept her promise.
Kathryn had worried what would happen if she died first. She wasn't sure whether Colleen could handle the stress of caring for Edwarda. "She can't understand why God did this," Kathryn once said of her younger daughter.
Mom had wondered: Could Colleen stand up to the task?
'A hole in my heart'
Colleen tried to live as normal a life as possible. Yet she couldn't shake her devastation.
Her sister -- her best friend -- lay in a coma. Her father was taken from her when she was 21. Dad had become her confidant. "I always had my dad to fall back on when my mom was tied up with my sister," she says.
It would be too much to bear for most anyone, let alone a young woman trying to find meaning.
She married in 1974, with the reception held in Edwarda's room. She gave birth to a son, Richard, in 1976, just eight days after her father died. Colleen's marriage lasted only six years.
The divorce was yet another bad blow. She and her son moved in with her mother, and her boy became a fixture alongside Edwarda.
"My marriage fell apart and I didn't feel like I belonged anywhere," she says. "That's when I ventured into drugs. I was just trying to belong somewhere."
Her troubles spiraled further. She was arrested on an array of drug offenses in the early 1990s. She was sentenced to nine months in prison at the Broward Correctional Institutional.
Being locked up, she had an epiphany: If something happened to her mother while she was behind bars, Edwarda would have no one to care for her -- all because of her selfishness.
"I went to prison and turned my life around," she says. "I knew where I belonged."
She took a job as a horse trainer, not too far from the family home. Many days she wished she could put Edwarda in her car and take her to the stables.
When their mother died, Colleen immediately quit her job. She suffered from multiple sclerosis but quickly figured out a way to manage her sister's needs.
"My mom worried I wouldn't be able to do it," she says. "But when you love somebody, you can do it. That's what you do for family."
And so she tended to her sister, day and night, for five years until that morning this past November.
"When I was down in the dumps, she would give me a big smile and it would just make everything seem like it was OK," Colleen says. "I talked to her just like I would talk to you."
She still rises before the sun, expecting to feed her sister. Then, her loss sinks in.
"I knew I loved my sister, but until she was no longer physically here I didn't realize how much I would ache," she says. "I feel a hole in my stomach, a hole in my heart."
In a quiet ceremony on November 28, Edwarda was buried next to her mother and father. Colleen was never sure what to make of her mother's visions of Mother Mary. Colleen had never seen the visions herself.
When she returned to the empty home after the funeral, Colleen walked into Edwarda's room.
There on the screen, she says, was an image of Mother Mary. "Not sitting on my TV, but on my actual TV screen."
It lasted for six seconds, then disappeared.