Cassidy Trevan was allegedly targeted by a group of girls at her school and was forced to miss her entire fourth year when the bullying became so bad.
When she returned to school they apologised and pretended to be her friend, but the following day lured her to a home where the alleged r3pe is claimed to have taken place.
Before she took her own life Cassidy wrote a powerful letter to fellow pupils describing her horrific ordeal and complaining that staff at the school "did nothing" after she was r3ped.
Cassidy was in Year 7 at a public high school in Melbourne, Australia, when the alleged bullying began with insults and then physical violence, her mother Linda said.
She claimed that the girls would make vile comments about her daughter on social media and follow her around local shops as they taunted her.
She missed her fourth term at school in 2013 and attended a recovery programme that gave her the confidence to return to school for two days a week.
It appeared her torment was over as the girls who allegedly bullied her apologised and invited her to join them at a festival the following day.
But it was all part of a plot to lure Cassidy, then 13, to a house, where she was gang raped by two older boys she didn't know, her mother claimed.
Afterwards Cassidy wrote a powerful letter warning fellow pupils about what happened.
She wrote: "I’m worried if they could do it to me they could do it to other kids like me, or at least try to.
"You actually have the power to stop this from happening.
"I’m not doing this for revenge to those students that r3ped me, set up the r3pe, bullied me about the r3pe, teased me about the r3pe or anything like that.
Linda said her daughter spoke to police after she was r3ped but was scared to make a formal statement because she thought the bullies would seek revenge.
The case was ultimately dropped.
Linda said she reported the incident to the school but was told it was a matter for the police.
She tried to move Cassidy to two different schools but the teen was suffering from flashbacks, panic attacks and PTSD.
Linda wrote about her struggle in a Facebook post which has gone viral, and blamed Cassidy's bullies for her suicide in December 2015.
She called it a "disgusting hate crime", adding: "I had to watch my baby suffer for the next 22 months from these demons ... she worried you would find her and get her again, she went through continued bullying from some of you who managed to get to her by phone or social media, via others, even after what you'd done to her.
"She suffered flash backs of the crime, nightmares, insomnia, separation anxiety, panic attacks, PTSD and subsequent worsening mental illness." So sad.