Overall, a good model, I think. Especially given that you guys don't have much experience with female characters.
Model-wise, I have to agree about the forehead thing. While I know 18 has a big forehead in the show....Jesus. She's almost like one of the characters from "Coneheads." Except not bald, thankfully. *shudder*
Speaking of hair, it's really not too bad if the forehead is fixed, though the part is on the wrong side and should be behind her ear, but those nitpicks are easily fixed. However, I also think its a little too round on top, like she has a wig on top of a football helmet or something...
Her torso is a bit off like others have said, but not so horribly, and you did say you'd do some tweaking.
I don't care much for the feet, but I could probably say the same for the other models.
Not to be hateful, but the hands were just lazy.
As for the absense of the jacket... If there's only a 1500 poly limit, then it obviously can't go in.
As for the texture, most of the issues have already been thoroughly done to death.
I would like to go along with the guy that said her face is too snarly, though. That's just a matter of doing a little work on the eyebrows. I don't mind the lipstick for some reason, and if you wanna use artistic license in that respect, have at it. It could do with some lightening, though. Just a thought.
I could fix a lot of the complaints myself as I have a decent background in model tweaking, but I can't do much better with the chest or torso. Or feet. I can't even DRAW feet, much less render them... I could do some texture tweaking for the face, but I only have MSPaint...so it'll take some time. If the original artists don't mind, I can try my hand at working some of this stuff out and save you the work and henpecking. Just send me a PM or something.