She seems to read as a slightly different character in every drawing (I have that problem, too...)
The top two on the left read as much more boyish, to the point where it's actually really hard for the viewer to distinguish gender. Bottom middle is my favorite of the the whole bunch.
I think you need to really lock down a few things, like her facial proportions, face shape, eye shape, hair, etc. I notice the bottom middle does a few things different from the others, like:
- Much smaller facial features relative to head size.
- More defined head shape compared to the others which are all more or less ovals.
- Hair seems thinner and more breezy.
As for outfit designs, how important is she? You may or may not want to give her more patterned clothing or brighter colors, or a distinctive accessory.