Don't worry about the people in your class. Go straight to the principal and report it, write down all the times she did what that made you feel uncomfortable as best you can.
Since you're not very specific, it isn't clear there is anything illegal being done- unprofessional, yes, but not against the law. If that is the case, they may speak to her in private and watch her closely after that. If she is a new teacher, she may not realize she's doing it. If something more serious has happened - actual meaningful touching or anything more direct, that is a serious problem. If they speak to her privately, you may only notice her not doing it anymore, and nothing else.
But do go ask for a meeting with the principal, and let your parents know what is going on. You're still a minor.
· 3 months ago