Women are much smarter than men, so: why to make the effort to learn how to make profit with bitcoin, when they can smile to a man :-)
OK, just kidding. Women usually don't like trading because is too much like a videogame, and usually you stay alone in front of the monitor.
But I know some women that are fantastic forex trader, because they mix competence with female intuition, and have very good results.
That might be the reason why there isn't that many women in Bitcoin. Women like to spend money more than making it.
A remark: Women like to make men make money for them. And the funny fact is, it works!