On Twitter, people offered prayers in several languages for Davis, who is in a coma at a hospital a couple of miles away from the school.
Hundreds of students and other supporters turned out at the school's track on Sunday to pray and show support for Davis, described as fun, bubbly and caring.
"She is someone we need back, and we're hoping she gets better because Arapahoe won't be the same without her," LinsiAn Loadman-Copeland said.
Maggie Hurlbut recalled how she was upset in the hallway at school once and Davis, whom she didn't know very well, stopped to ask her how she was doing and offer help.
"She just wants to take care of others," she said.
Authorities believe she was shot at random by fellow senior Karl Pierson soon after he entered the school Friday armed with a shotgun, extra ammunition, a machete and three Molotov cocktails, looking for a faculty member with whom he had a dispute. Davis was sitting with a friend near the school library when Pierson shot her in the head point blank.
In their first comments since the shooting, Pierson's parents said they were shattered and devastated by the shooting and offered their thoughts and prayers for Davis, her family and the entire school community.
"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," Barbara and Mark Pierson said in a statement.
Pierson may have been nursing a grudge against a school librarian who coached the speech and debate team since September. Pierson excelled at speech and debate and was passionate about the team, friends said. They described him as a smart student who sometimes would get into debates with his teachers.
Pierson had been disciplined by the librarian for reasons yet to be disclosed, according to Arapahoe County Sheriff Grayson Robinson. He has said Pierson threatened that teacher in September and came to the school Friday intending to harm him and inflict numerous other casualties.
The coroner confirmed Monday that Pierson committed suicide by shooting himself in the head. Robinson said Pierson killed himself 80 seconds after entering the school because he knew a deputy assigned to the school was closing in.
The investigation into the shooting continues, but authorities have finished their examination of the school building. Students will be allowed back later in the week to get their belongings, but with the holiday break scheduled for next week, they won't be returning to class until January.