Avila left a final note before taking her own life last week.
"My whole world just came crumbling down", the tearful mom told CBS Los Angeles.
He also said the school failed to do enough to protect her and administrators need to take a tougher stand against bullies. "And it said, 'Sorry, Mom, you're gonna find me like this, '" Freddie tearfully recalled.
The grieving parents also shared with the local news outlet that Rosalie would write down in a journal numerous mean comments kids would say to her.
They relentlessly called the California teen "ugly" and made fun of her braces, her father Freddie Avila told ABC6. She apologized to her parents for finding her "like this". One of the notes stated, "Sorry, Mom and Dad". I go, 'You have braces, honey, don't worry.
Rosalie cut her wrists because of the bullying, he said, and kept a list of people who bullied her in a diary.
One twisted social media user sent them a picture of their dead daughter alongside a bed and a grave, with a caption that read: "Hey Mom". Below that, it says, "Tuck me in THIS", with an arrow pointing to an open grave.
"Now I know what my daughter was up against", Charlene Avila told NBC News. "When you are being harassed and intimidated in school and in any form on social media, it's very hard to get away from that". Rosalie chronicled her feelings about the alleged verbal abuse in a journal, which her parents have turned over to police.
The family said they plan to donate their daughter's organs.
On Friday, her family made the hard decision to take her off life support.
A GoFundMe to raise money for funeral expenses raised almost $40,000 in three days.
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He lamented that his daughter's bullies were alive and walking the halls of Mesa View Middle School as he planned to bury his daughter. Her parents say their daughter was mercilessly teased by her peers for two years.
In a statement, the school district said that "no one can fathom the heartbreak and confusion that we are certain many of our students and their families are feeling right now, especially the families of those students that have been most closely struck by this event". "She's very smart and always had good grades", the page read.
"No one can fathom the heartbreak and confusion that we are certain many of our students and their families are feeling right now, especially the families of those students that have been most closely struck by this event", the December 1 statement had said. She loved the beach & liked going out to the snow. "The world lost a treasure".