Six-foot Morgan Musson took an overdose of painkillers and was found dead in bed at her home in Basford, Nottingham.
Her mother Debra Savage said Morgan had been a pupil at Ellis Guilford Comprehensive in Basford when she was allegedly bullied.
Morgan had started a new school in September.
But her mum said she was still affected by the alleged bullying and not enough was done to protect her.
Nottinghamshire police have been asked to investigate the bullying claims.
The school won't comment until the inquest is finished.