Rehtaeh Parsons, 17, died Sunday in a hospital after attempting suicide a few days earlier.
Four boys allegedly raped Rehtaeh when she was 15, her mother told the Canadian Broadcasting Corp.
After a year of investigating, police told Parsons there was not enough evidence to file charges, and the photographs of the act did not indicate a criminal issue.
Parsons said other students began bullying and tormenting her daughter.
"She was never left alone. Her friends turned against her, people harassed her, boys she didn't know started texting her and Facebooking asking her to have sex with them since she had had sex with their friends. It just never stopped," said Parsons.
Many people have expressed outrage that more had not been done to help Rehtaeh, CBC said.
An online petition demanding an inquiry into the police investigation now has more than 2,000 signatures.
Nova Scotia's Justice Minister said Tuesday he was asking his office to look into what actions they could take on the case.