The mother of a teenage girl stabbed at a Sydney high school Thursday morning was “shocked” to learn of the attack, claiming the school neglected to contact her.

Lapini Maile told friends on Facebook that she was not phoned when her daughter Alisi Maile, 15, was stabbed in the shoulder with a metal ruler at her school.

“When I heard the news this morning about my daughter I was shaking, crying and most of all worried about my daughter,” she wrote.

Mamamia reported on Thursday two students and a teacher were stabbed at Bonnyrigg High School shortly before 9am.

Year 11 student Alisi, along with a 16-year-old boy and 48-year-old science teacher, Carolyn Cox, were treated for non-life-threatening injuries sustained in the attack.

Ms Maile did not say how she found out her daughter was one of the victims, but said she was upset she was not immediately contacted by the school.

"And the thing that upsets me even more is that the school didn't not contact me or the emergency contact number that I provided to them when they were supposed to contact me immediately as soon as it happened," she said.

"Please parents be aware of what is happening at your child's school. I hope that this does not happen to anybody else's kids."

Ms Maile shared the post on Thursday afternoon along with pictures of her daughter recovering in The Children’s Hospital at Westmead.

A 16-year-old student has been charged with wounding with intent to murder and two counts of wounding a person with intent to cause grievous bodily harm following the alleged attack.

Mamamia contacted the school however they declined to provide a response.