What is the ruling on a teacher helping her colleagues who cheat students, when she herself refuses to cheat, and is she sinful for not being able to prevent cheating in the school?

What teachers do by writing exams on the whiteboard is a great betrayal of trust, and they must repent of this betrayal. It is not permissible for the questioner to weaken and participate in their cheating by informing them of the questions. What is required of her is to advise the administration and the teachers and remain firm in her stance on the prohibition of cheating.