I'm a female playing a female character. I've been told that my use of proper grammar/spelling gives the impression that I'm a guy (seriously???), but my excessive use of emotes gives the impression that I'm a girl.

As far as the... "men tend to jump around and women stand still" anecdote... I tend to run laps around my FC house while I'm bored, talking on voicechat, or waiting on a queue.

Truth be told, it's hard to tell. I've heard many people say stuff like, "Oh I can tell that girl was really a guy..." or, "I have a feeling that person is a girl..." The best thing to do is just to ask. I tend not to bring up being female, unless it's relevant... although once people hear my voice, the answer is pretty obvious.