(CNN) -- Hannah Anderson mourned alongside family, friends and strangers on Saturday at a public service remembering the lives of her slain mother, Christina, and little brother, Ethan.
A crowd of about 500 filled every pew of Guardian Angels Catholic Church in Santee, California.
Mourners listened as Father Kevin Casey opened the service with a prayer for the lives lost during the tragic incidents of August 4.
"We are here to pray for Tina and remember her, and for Ethan. Ethan doesn't need prayers. He is already an angel in heaven. And that is our great belief," he said, "all of us would like to take away the awful pain that was inflicted on Hannah and on the whole family. We ask God for resurrection and light in this darkness and death."
Christina Anderson, 42, and her son, Ethan, 8, were killed by family friend James Lee DiMaggio, who then set fire to his house and kidnapped Hannah, authorities said.
In the days after the kidnapping, a multistate manhunt ensued, ending hundreds of miles away from his San Diego-area home. On August 10, horseback riders spotted DiMaggio in the Idaho wilderness. An FBI agent shot him dead and Hannah was rescued.
A playful snapshot of Christina and Ethan adorned the church altar, along with a photo of the family dog, Cali, also killed by DiMaggio. Their remains were held in urns, encircled by family photos, flower wreaths, cards and a football meant for Ethan.
"As you know, Ethan was so handsome, full of spirit, loved football," Hannah's great uncle, David Braun, said during the eulogy. "What a kid to have as a son, or a brother, or a member of our family. You just wanted to be his buddy."
Several of Ethan's football teammates listened from the back of the church as Braun reflected on the life of the boy they knew. They wore their black and yellow football jerseys in honor of Ethan.
Braun also spoke kindly of on his niece, whom he lovingly called "Tiny Tina."
"She was a devoted mother and a wonderful person to have in our family. Very devoted to her children, full of life and always ready to help out if you needed a friend or a favor," he said.
Hannah, 16, listened from the front row, where she sat surrounded by her maternal grandparents, Sarah and Ralph Britt. Her grandmother had her arm around her for most of the service.
"We will miss them forever. We will always remember them and ask, 'What could have been?'" said Braun.
"It has been very painful. It has been unending pain and sorrow," he said. "We have all felt your pain in an every minute since this attack on our family transpired."
Braun thanked family members for their support, the media, the FBI and the ranchers who are credited for Hannah's rescue. He told the congregation Christina and Ethan will never be forgotten.
"They say only time will mend a broken heart but who knows, only time... but those we will those we love will never be more than a thought away. For as long as there is a memory, will live on in our heart."
Hannah arrived at the service with her father, Brett Anderson, in a black SUV. Before the start of the service, she greeted and hugged churchgoers and thanked them for their support, including several of her classmates who sat towards the back of the church.
Hannah then joined her family and the congregation as it sang "Amazing Grace" and a procession gave way to the Holy Eucharist.
CNN spoke to Hannah's grandmother after the service ended. Sarah Britt described the service as "uplifting."
"It was a chance to finally celebrate my daughter and my grandson. With waiting to find Hannah, we had to put our grief aside to this day. It was very uplifting and my daughter would have loved it," she said.
Britt said Hannah "did really well."
"She is very strong. She had a few moments, but she is very strong," she said.
Britt said she plans to raise Hannah, who has plans of becoming a firefighter.
The family handed out a memorial card that included a prayer verse and a message that read: "We express our heartfelt gratitude to all of you in our time of need. Thank you, The Anderson and Britt family."
The card included a photo of Christina and Ethan. Christina's death date was listed as August 3, and Ethan's as August 4.