First and foremost is the eyes- for lack of a better term they're simply incorrect. Her left eye is far too lopsided. Overall the face needs to be redone entirely- chin, cheeks, mouth, etc.
Next- you seem to disguise a massive amount of the body in black, effectively hiding a lot of errors in proportion and eliminating any sort of depth detail as well. My suggestion is never use pure black- stick with a very dark navy. Another suggestion, if this was intentional, would be to practice instead of hiding it.
A simple/lazy method of adding a bit of detail/light source would be airbrushing white or grays onto the body where your light source hits.
I like what you did with the light stream coming from the weapon though.
