I have a two year old and I can tell you fighting against pinky-princess girl culture is a battle. As a parent, it's you vs basically the rest of society that sends a million little cues about what girls are supposed to do. I had this conversation with my daughter the other morning:
Daughter: I want to be a boy when I grow up. Me: Why is that? Daughter: So I can be an astronaut!
Of course, I explained that girls can be astronauts too. And I've never done anything to set her expectations differently. But they just absorb this stuff from the ether of our culture. At her age, she's picked up on the idea that only boys are astronauts, and girls are ballerinas and princesses and shit.