So, a friend started up a big ol' game project (who knows how solid it is, but I need an excuse to do a lot of pixels), and she plans a fighter of sorts with chibi, pocket/gem-fighter-esque sprites. For now, she just wants to see what sort of stuff I can produce.
I'm working from a reference given by someone in the project with much better traditional media skills than I, here:

This is what I came up with:

Not a bad start, I don't reckon, but I know it could be better.
I suspect that this will be displayed at 2x, FYI
Issues I see:
-In my image, Jetta's shoulders/hips/feet don't quite seem to line up, but I feel like they match the reference pretty well, where they DO seem to line up. Perhaps it's in my shading?
-My face doesn't quite match the reference. Its curves in the jaw especially don't seem to match up. I suspect that I shouldn't quite expect pixels to curve like that, but I do wonder if I could do this differently.
-The boots look rather muddy. Would it help to use a contrast color in there to define the lines a bit? If not, what else could I try?
-The linework is a bit harsh in a few places, I'm just noticing, but that shouldn't be too hard to fix.
Thanks in advance.
Update:
No comments or critique, but w/ev. The work goes on! I've messed with this enough. I'll call it final, I suppose:

->

Added dress detail, and brightened the outline colors a bit, which softened them a bit. Dropped a colors that didn't add much, particularly with the glasses, which I made blue instead of the greyish that they were. Then I yellowed the eye whites a touch for contrast.