(CNN) -- Friends of Claire Davis, the 17-year-old senior critically wounded in Friday's shooting at a Colorado high school, are wondering why bad things happen to good people.
Davis is in a struggle for her life at a hospital in Littleton, near Arapahoe High School, where a classmate shot her in the head.
She remained in critical condition Sunday.
"She is stable, but is in a coma. The first responders got Claire to the right place, at the right time, and the doctors and hospital staff are doing a wonderful job taking care of her," her family said in a statement.
"We appreciate your continued good thoughts and prayers, and will provide updates as her condition improves."
Among those praying for Davis is the family of Karl Pierson, the 18-year-old senior who police say shot her. In a statement released Monday afternoon, Barbara and Mark Pierson said Davis and her family "have suffered unimaginably, and we pray for her full recovery."
"As parents, we loved our son Karl dearly and we are devastated by what happened Friday. We cannot begin to understand why Karl did what he did," the Piersons said. They also offered prayers "for the entire Arapahoe High School community, as we know your lives are forever changed by this horrific event."
Police say Pierson was looking for revenge against a librarian, but couldn't find the faculty member and killed himself as a school resource officer closed in. Davis was just a random victim, police surmised, and the gunman and victim didn't even know each other.
Davis' classmates spoke well of her. They used words like spunky and bright.
"She was just a very sweet girl. She's really smart," August Clary told CNN affiliate KUSA. He said Davis loves to ride horses and "wouldn't hurt a fly."
Hundreds of people attended a vigil for Davis on Saturday night.
Katie Snively, a senior at Arapahoe, said it was important to honor and pray for Claire.
Many people were tweeting to the hashtag #prayforclaire.
"Claire is a hero. our hero. she deserves to be rewarded not only with thanks, but with another chance at life," Aidan Loughran wrote.
"Thank God for waking us up again and for keeping Claire through the night. Don't forget to pray as we wake up this morning," Jonathon Bailey tweeted Sunday.
Davis' father told CNN affiliate KMGH late Saturday that his daughter is "not doing very well." The station said doctors are worried about swelling to her brain, according to a family friend.
CNN's Casey Wian contributed to this report.