I believe that there is a market for girls who read comics, I know this because I met a bunch of them, and I do believe that it's just a matter of time when all of that will sort itself out.
I'm so sorry to hear that DC has decided to end its barely one-year-old Minx graphic novel line, which was geared towards girls. It had some good stuff, especially my girl Castellucci's PLAIN Janes series (well, just a duo now, I guess). I'd like to be as optimistic as Cecil, but I'm afraid that the rest of the comic industry won't be - I'm afraid this will be taken as proof by a lot of people that girls just aren't a viable comic audience. Although I have my own serious doubts at how well Minx was marketed and promoted, not to mention the fact that they only gave it little more than a year's time to experiment. It's just too bad.