It looks likes you have the basics of what it's supposed to look like. Keep practicing, add in more layers and different shading and work on getting everything to blend together.
Well, let's just say you can tell it's your first, but I'm sure you'll improve. Try using the pen tool and rounding the edges, or using the pencil tool... Just a suggestion. And make the eyebrows more visible.
It's...interesting. I mean it doesn't follow the typical shading styles of vexel art. It's very choppy, and theres few layers, yet I think just about anyone would be able to tell it's Hilary. I think it's great you don't try to make your work look like everyone elses.