When I first joined I thought it would be strange to be referred to as a girl. Had a male screen name and didn't think I would want to be called by a female name. I can't quite remember why it changed. Now I don't mind, actually kind of like it.
I think Persephone gives some good advice. Naturally this place has some blurred lines when it comes to gender and things can be pretty muddled on how to refer to each other. A helpful reminder for others would probably go a long way.