I think this portrait would benefit from more contrast; right now, it looks a bit flat. Next time, you may also want to position the subject further away from the wall, so as to avoid having that strong shadow next to her head. Finally, although portraits are sometimes taken with soft focus, here I'd prefer to see her eyes sharp.
I like the catchlights in her eyes, and her expression - her mouth seems to be on the verge of smiling, her eyes are smiling already.
I've adjusted the levels and sharpened the photo slightly in PS to illustrate what I mean. The conversion to B&W is purely a matter of personal preference.