To my eye, there are a few things that could be changed...
The pose looks kind of awkward for the model.. I think having the jaw pointed up as much as it is is with the head having slipped down off the pillow. With the head bent back like it is, it doesn't "flow" well, for me for some reason.
The image, as you've posted it, doesn't have a full range of tones. The whites bottom out just past middle or light gray, giving the image a rather somber tone. Just a quick change in Photoshop would add a bit more range of tones (albeit compressed - I can post or email you a copy of what I mean). Originally, a bit better exposure would have brightened the image up into a "sunrise / early morning" feel instead of a "dark overcast day" feel to the image.
Do you remember where your focus point was? I'm guessing it was at the top of her head, which with your DOF throws her lips out of focus. I'd prefer to have seen more of her face in focus.. maybe put the focus pont at the bridge or tip of her nose to keep her whole face in sharp focus while allowing everything else to go out of focus.
Fear not, though.. if it hadn't been a pretty good shot to begin with, it wouldn't have caught my eye enough to car about critiqing it.