History of Feminism

I would send an email to the principal about this. But I would.

Though it might not seem so, the ultimate authority in schools are the parents. I would send an email, and say this has happened, and say you want to make sure that the principal is aware that older boys in his/her school are touching younger girls inappropriately and uninvited.

I would insist that your child's confidentiality is honored, but I would suggest that the principal hold a session for both the boys and the girls in which inappropriate touching of each other is discussed, and the consequences for that inappropriate touching in school are laid out.

I would make it clear that any escalation in uninvited or inappropriate touching among students would reflect REALLY badly on the principal and he/she needs to nip it in the bud.

You probably won't get any results from this email. But you will definitely hear about something like this happening again. When you do, send another email and point out that there is an issue that isn't being addressed. Each time you hear about something, send an email. Then you have a paper trail, and can threaten parent action after your own child isn't the only target. If there is still no action taken, bring it to the PTA.

This isn't OK, and it's a great time for the kids to learn that in a non-threatening "here's-how-you-act-like-an-adult" way. It also institutionalizes non-acceptance of this in the school, which is a good thing.

Eta: I think I'd go right past the counselor on this. Your daughter doesn't need counseling. This isn't her issue. It is the school's issue, and the school should take responsibility for it.