How would identify a female player guy/girl?

[Tsuga]

Meh. I am straight, but I look better in a skirt than most women I know. If people perceive me as gay for what I wear then they are just jealous of good fashion sense. I could care less if people think I am gay, IRL or in game. My sweetie knows the truth and she is the only one on the face of this useless ball of dirt that matters XD

This made me super happy to read

P.S. - When she is logged in to any game, I have informed her that she is indeed a guy as far as the player base is concerned

That's a safe call, and she'd better be careful not to mention that she's ACTUALLY a girl irl, otherwise she's just an "attention whore" exploiting her gender for favors.
Also make sure she jumps around a lot just to drive home that she's a dude. I hear they tend to do that.

I've learned so much from this thread.