She has a neat, refined design, and the slight line change that defines her calves is simple but adds a lot. I suppose it would do good to draw eyebrows, and give her boots more boot-like qualities. Right now they look to me soft and pliable like socks, yet they have a hard heel.
I'm thinking something that is more shapely to her feet and legs, like maybe some variation so the ankles are more defined. Of course, it's only a suggestion, so if you like the style it's all good.