They believe the school did not respond adequately.
According to the lawsuit filed by the family, Mallory ate her lunch in a guidance counsellor's office in order to avoid bullies.
She was also allegedly forced to hug one of her bullies as an attempt at reconciliation.
According to the grieving mum, those who bullied her daughter have not been punished despite the tragic outcome.
Grossman has become an anti-bullying advocate and has started a group called "Mallory's Army" to honour her daughter's memory by fighting for others being bullied.
A GoFundMe campaign is raising money for a memorial to honour the child.
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Samaritans 0800 726 666
• If it is an emergency and you feel like you or someone else is at risk, call 111.