Yvette Velasco is being described by her family as smart, motivated and full of life.
In a statement, her relatives said she was "loved by all who knew her."
"We are devastated about what happened and are still processing this nightmare," the family said.
Velasco is survived by her parents and three sisters.
"Please pray for our family and the other families who have lost a loved one as a result of this terrible tragedy," her relatives wrote.
In the aftermath of the shooting, Velasco's relatives searched everywhere for her. Mindy Velasco, her aunt, called hospitals, police and evacuee centers in a harrowing search for information, the Los Angeles Times reported.
"I'm fearing the worst," she told the paper. "She would definitely be in contact after something like this."
Elizabeth Faron, a friend of Velasco's from college, remembered her friend as "amazing, very sweet, friendly and affectionate."