From my humble experience, girls who play games either don't tell anybody unless they just "happen to find out" or they'll boast it for attention.
Just like there are girls who are humble about their looks, and there are some that act like whores.
Should they do it? Hell, I don't know. But what I do know is that they're looking for attention, and I personally don't like attention whores. But that's just my take.
EDIT: I should include that yes, a girl gamer is much more attractive than one who isn't. But the above comment still applies to this.
And as a side note, (from what I've heard) the girls that really want to fit into the gamer community never end up being able to like a guy could because of their gender.
And you know what? That really pisses me off. I keep hearing about girls getting harassed on Xbox Live and steam from the first inkling that they might have boobs. It's seriously annoying considering I do know someone that likes to play console games but can't play online and socialize with other people due to their gender. It's really sad, and really immature.