Perhaps harsh, but I'd toss the whole thing and start again. Rough out what you want shapeways more than focusing on the style mockup. For example, in the smaller sprite her hair has a ton of volume to it.
Work out guidelines for the head shape, the face, and then the hairline, then start using THOSE as guides for the expressive shapes you want to put in.
I'm sorry if that's confusing, I'll try to clarify any points that don't quite make sense.