Some girls play with dolls.
Some girls get to wear pink and purple.
My girl has a brother. She has been watching her brother since the day she was born.
This brother of hers taught to play with trucks and cars. He showed her that it is was OK for little girls to play with boy things. He showed her if she plays with trucks and cars he would play with her too. So she plays with little boy things. And loves it.
He doesn't know it but he is a wonderful teacher.