Beautiful! Looks really solid, man!
Kate is best gril >u< I tried drawing her before, it didn't look as good as I imagined it would so I didn't share it lol
Are you using Bluefley's square brush?
There are a few tiny things you could add to this to make it more interesting, read about subsurface scattering, it's tiny little trick that you could do to make your drawing look more alive :D