Well for me personally, I started training martial art at all because of the principles behind it: Honor, discipline, self-control, etc. When I came to College, I started Muay Thai and some other stuff mostly because my big brother was here and that's what he taught. I continue taking it because, especially mixed with Grappling, it's really stinkin' effective. I personally enjoy the science of body motion, and while I do ballet and things too, martial arts are a deeper art to me. This is because it allows, not just the opportunity for precise technique, but also the ability to take information from your partner and insert the most perfect response. Also, understanding the destruction involved is essential to understanding compassion.
For other women, I've seen it massively boost their confidence, though sometimes they pass through a phase of having something to prove, where they feel they have to defend their right to be strong. Right now I can be pretty girly at times, but I know I'm a decent martial artist, so who cares? I even reserve pink as my color of choice in training cloths, if nowhere else in my life
Another point to consider is that martial arts are great for self defense. This is NOT because it turns women who suck at fighting into women who kick ass. It's because it turns women who don't fight back at all into women who aren't afraid to use force. Go to a self defense seminar on campus sometime. If there's an activity like kneeing a pad, the guys will be all over it, and if you get the women to participate at all, they rarely put any force behind it. I didn't believe it until I saw it repeatedly, I mean, we had a women's revolution, right? Because of what we do with our free time, we're used to the women who're in martial arts, and have been there a while. But an interview of sexual predators and muggers showed that they chose women as targets who looked like victims, and when they attacked, the women froze. They usually didn't even scream, though when they did make a fuss, the attacker gave them up as too much of a risk, and left.
I guess I got off topic there, but I hope this was useful anyway. So here you go, a little brain pick of some female possibilities. Hope it helped, heh.