This is a long shot and maybe depend on the school and teacher but could you talk to them about it and see if they would talk to her? I am a teacher and am unsure how this approach would go down as well to be honest but I think as you said it is really important that someone says something and asap.
I think you would be completely compassionate and understanding in the way you approach it with her knowing that you have been through it yourself :hug: but how she takes it is anyones guess. She might initally be in shock and avoid you initially but then be very thankful later. I would be inclined to talk to her about it.
ETA: THe more I think about it the more I think talking to the school may not work :doh: Tricky one.