"It should be the bully that leaves."
George's daughter rang her last Friday crying for her mother's help.
She alerted school staff to the situation and drove to the college.
George claimed the attack on her daughter was unprovoked and came after months of bullying, largely to do with the colour of her hair, Fairfax reported.
George said she has lodged an assault complaint with police.
But bullying of her daughter had continued on social media, George claimed.
"She's a mess. She's too scared to go anywhere on her own now."
Nelson College for Girls principal Cathy Ewing confirmed to Fairfax an incident took place at the college, but said it was school policy not to comment on the details to protect the privacy of students.
"The school ensures that all matters of student wellbeing and safety are dealt with promptly and properly," she wrote in a statement to Fairfax.
"We do not accept bullying and violent behaviour within our school. We require our students to follow our school rules and take pride in the high standards we expect."
She said "appropriate disciplinary action" was taken and support processes were put in place for both students.
The incident had reportedly been referred to the school Board of Trustees.
The Ministry of Education was also notified of the incident and was working with the school, Fairfax said.
