Having a boy in the women's bathroom is no big deal to me, unless he's peeking under the stalls -- but NO kid should be doing that.

I think one of the more important things to teach a kid is that when there are other people around, getting attention is maybe your best defense. Scream something embarrassing, throw yourself on the floor, and don't fear being looked at -- you want that. I had a man following me in his car when I was walking to a bus stop and he left FAST when I shouted out that I was underage.