I also see elementary (majority female) school teachers actively encouraging boys not girls to the point where it makes me sick. More so given the amount of women that act as though women doing worse/having less confidence in Maths in part of some sinister male conspiracy.
I am putting my money on something (Oedipal) that makes the female elementary teachers treat the girls differently which a lot of girls see as disproval for being good at Maths and once this is internalized it is hard to turn around.
My DD9's gifted math teacher is a woman. One project the kids were assigned this year was to research a famous mathematician, and write a report on who they were, and what they did to advance our knowledge. When I heard about it, I immediately started to think about the ancient Greeks and Arabs, but a couple days later DD had been assigned to Mary Pensworth Reagor. I took this as a subtle declaration to DD that, "You WILL have positive female role models."
In another thread I recently said DD has had a couple of awesome teachers... this lady is one of them.