Rails Girls
kiwiluv.com
kiwiluv.com
I'm thinking that if you want to attract women, you should refer to them as "women", not "girls."
But were you attracted to the field because it was presented as an activity for boys?
You might also ask (as the proper counterpart to your advocacy for using "women") whether I might have been had it been presented as an activity for men. Probably not, because I didn't identify as a man when I was a boy.
All I'm saying is that there's no reason to be hypersensitive about using the word "girls" if your target audience actually includes them. Is there a reason to believe that they were using the word "girls" but excessively trying to appeal to women? I took the unicorn and the kitty as a dead giveaway, myself.