There just aren't nearly as many female guitarists compared to male guitarists (probably because of the reasons you mention in your first couple of paragraphs). It seems there are more nowadays than there used to be though, and more every day. Check out Jocelyn Celaya/Radical Classical, I just discovered her the other day:
http://www.youtube.com/watch?v=NjrYuZOverc
http://www.youtube.com/watch?v=BBYXAirl4KY