Who raised those brothers who won't let sisters come to the mosque? Mostly women. For all the talk of Muslim women going out to change the world, we tend to forget about the one place where women have the most control: as mothers. Use this power.
It's mothers who can perpetuate notions of what a woman's place is, and they also can perpetuate a lot of the misguided notions about the position of women in Islam. Think through what messages you are giving your children. For example, how many mothers spoil their sons by not insisting they clean up their own room, put away their own dishes after dinner, help clean up the house or fold the laundry? Mothers can and should challenge gender stereotypes in their own homes.
This may be considered a small step for moms, but it leads to big steps for Muslim brothers.
With regards to daughters, mothers must orient them in the right direction on a personal level as Muslims, then at the academic and career levels. Not to forget but mothers are their daughters first role model. Be an example for her of a solid, strong Muslim.