Yeah, most new members don't bother being active. Besides JF, all the other active "girls" are just guys who changed their profile genders to help the girl team win a forum game. :P
These are all the female members I can remember off the top of my head:
Jesus Freak (a.k.a. Strong Bad)
Walkazo
Turboo (a.ka. Blue Toad)
Rosalina Spalko
Grapes
Fawfulfury65
Princess Alyson Koopastool
There's quite a few more than that, but that's all I can remember right now. The first three on that list are the only ones that log on on a regular basis, though.