I don't consider myself a girl gamer, really, because I'm not a gamer. I probably used to be. I was better than most men I knew at SSX and the other games we'd play on rainy days.
I think it's a pointless argument, to be honest.
But also, I do think that women are generally crapper than men at games. I'm not a mysogenist here, hold on. It's also the reason why there are fewer female guitar players. Things like long games and guitars take long hours of attention, pickiness, and general fiddling about. I have never met a female who could be bothered doing all the side quests in RPGs and learning all the combo attack things in fighting games. I've met a few who are pretty good at Halo, but that's mostly just so they can beat their boyfriends at it.
However, one game women destroy men at - The Sims. I have never met a male who plays the Sims, and would frankly have to look twice at a man who told me all about this ace ****ed up family he'd made and the nice house he built for them. I have never known a man make a 'sim' version of himself, and then a 'sim' version of the person they're interested in, and then bred them. Sadly, I have known women who do this. I am pleased to say that I am not one of them. I play the Sims when I have nothing to do, I'll admit. But I play for fun. I have a woman called Peace of Westphalia who has 9 kids to 8 men, and she dresses like a total ho. It's ace.