I would like to add to this, I have really tried to demystify female stuff like menstruation and breasts. Having an older sister go through puberty helped with that, but when I was a kid, it was fighting tooth and nail to get the same-gendered parent to talk about sex with you. No way they were going to talk about the girl stuff with the boy and vice versa. I think that lack of exposure leads to treating each other badly--perpetuating stereotypes out of ignorance (girls on their periods are bitches and smell like fish are two I remember were rampant when I was a teenager). Wet dreams, “hard-ons” were a subject of teasing girls used a lot.

Education, as usual, and modeling are key. Above and beyond what the school provides.