Did you scale down a larger image as a basis for these? The eyes and eyebrows look blurry.
I'm not really sure what sort of feedback you're looking for, so here's my attempt at general improvements on the left character's face while keeping your style:
Gave her a chin, and moved the ear down as it was too high. I also changed the shape of the back of the jaw, looked like it has a weird bump on it before. Aside from these changes, I did not adjust the anatomy, as I don't know what was intentionally stylised and what wasn't.
Made the eyelashes and eyebrows darker, as before they didn't read well. When you have only a few pixels to work with, you need to focus on clarity over realism, even if it means eyelashes that look darker and thicker than they "should".
Got rid of the middle skin shadow colour as it wasn't doing anything useful. Even darkened as the shadows are now, I still think they're too light. I recommend using darker shadows all around, unless you're aiming for a washed-out look.
Both of them have very large heads. Since the bodies and heads are otherwise realistically proportioned, that looks weird.