Then, during Sunday's final show, gunfire erupted. Amid the barrage that left 58 people dead
, a bullet struck Rosemarie Melanson.
"It penetrated her stomach, it penetrated her spleen, and it also penetrated her lung, and her liver took the brunt of the force of the bullet," the woman's husband and the young women's dad, Steve Melanson, told CNN's Poppy Harlow.
By Friday, Rosemarie Melanson had undergone her second surgery and had developed a complication with her kidneys. She remained in critical condition on life support.
"After talking with her doctor, she had more damage than we thought," Steve Melanson said.
'Mom is down'
When the shooting started, it tore apart a day meant for the women of this family to spend together.
"We were so excited that she could come this year," Stephanie Melanson said, referring to her mom. "So, it's hard that we finally were able to take her and this is the outcome of it."
Steve Melanson recalled getting a text from his wife moments before the chaos began.
"My wife texted me and said she's having so much fun," he recalled. "So, we had a small conversation by text. And Stephanie texted me with the same happy thoughts of how much fun they were having.
"Shortly after, within five minutes, I got a text from Stephanie saying, 'OMG, OMG.' So, I thought maybe they saw somebody," he said. "And then, the next text was, 'There is a shooting in front of us.' The next text after that, 'Mom was hit and Mom is down.'"
For the next 11 hours, Steve Melanson didn't know where his wife was -- or whether she was dead.
'Your mom is strong'
As the horror unfolded, Stephanie's sister, Paige Melanson, also was grazed by a bullet as it whizzed by her arm.
"It was horrifying, really," Paige Melanson recalled. "I got separated from everyone. I was taken by ambulance to the hospital to get treated for my arm. But because there were so many more people that were so much more severe than I was, I was in and out."
"From there, I had to go home and tell my grandma ... that there had been an accident," she said.
Paige Melanson stayed by the 88-year-old woman's side until news of the rest of her family, including her mother, arrived, she said.
"The second we were informed she (my mother) was found, we were down at the hospital," she said. "Then, as soon as I saw her and made sure I saw her breathing, I went and checked myself back into the ER."
Days later, the family met President Trump and the first lady when they visited Las Vegas
. Both were "really human," Stephanie Melanson said.
"They had a heart. They were caring. They were sympathetic," Stephanie Melanson said. The first lady "got up and just bee-lined over to us and just hugged me and told me, 'Your mom is strong. She's a fighter. She'll be OK.'"