Nice job, and to hell with realism!
I think it's a nice mini... the only thing I'm not bad about are her eyebrows, they're a bit too thick for such a feminine face!
This miniature (along with a couple of others) were done for my wife who has a thing for big guns; they were supposed to be a bit tongue in cheek; i.e. babes with big guns. Obviously almost nobody besides us views them that way. As to her actually weilding that weapon, in the actual game Pi is a cyborg and her right arm (holding the weapon) is robotic, I imagine it would have little trouble hefting a weapon that size like that, but whatever. The symgbol is a stylized eagle's claw done over a diamond pattern, it turned out a bit too busy (tried to keep the diamonds pale to help the claw to stand out but it didn't help as much as I would have liked, should have made them more subtle) And yes, it's freehand.
I don't see what the big deal is with oversized weapons. Afterall, all of the regular Celtos and Void chicks come with weapons that are longer than they are tall, and probably weigh twice as much as the gal! So what if someone did a convertion that follows the norm?? I don't see people complaining about the unrealisticness of the "normal" models. ;P I think her hair is great and I like what you did with the ends of the flamer.. Also, what's on her shoulder-pad? Is it free hand?