I like it. It's simple, and simple sometimes can be the best.
All in all, its good for your first.

Only one problem, something about the outline of the ponytail isn't right.
But all in all. Goodjob! :)

Hello, and welcome to the forum! I agree wholeheartedly with devinaaron, in that it's a lovely simple start. The thing that stands out to me in terms of criticism is that this is a very small sprite, so including black outlines inside the main outline can take up a lot of space. You didn't do it around the hair tie of the boots, and that's fine. Some outlines can work, and I'd say some places really do need the definition, but full black is a little intense. Another thing to think about is that dithering is much less effective at smaller scales. Try using shapes of colour, or "clusters" for lighting and shading rather than dithered patterns.

Happy pixeling!