As far as I can see the mouth looks great, so does the outstretched arm. The right arm looks a bit bulky for a Mithra arm and her upper torso is shifted too low. Shift the breasts up a little higher and make them um... more... perky? Right? Right now she looks like she's not (even though she isn't) wearing a bra. It also gives the look of being older, less toned. Mithra are agile, small, and lithe. Try to stick to those three words and it'll look great. (Also a good idea for reference shots is to look at smaller female bodybuilders and how their body is shaped. The only problem is that looking for them may get kinda scary.) In the background you might want to have him farther away. It may look cool at first, but she's got a katana in her back. >_>; Or will soon. Blur his lines a bit, possibly using a thin pencil or pen for the outline. When colored, it can give the sense of being in the fray with action all around, but the camera is focused only on her. (Like a really good sports photograph.)
Sorry for the critique. ^^;; It's looking great.
. I'm not very good at coloring so I'll be asking help from Qserver's finest :wink: 
