I've had to come back to this one a couple of times as I couldn't put my finger on what was bothering me about it. This time I got it :) Contrast. Maybe even a play around with levels adjustment? Something to get the blacks deeper, whites lighter and the colours to pack a punch. Other than that, awesome portrait composition. Good luck!
This is far too lovely a model not to do some Photoshop work on it.
Add some intensity with curves or levels in PS Elements if you don't have photoshop.
Add a layer mask and blur it with a light gaussion blur, then erase the layer over the eyes. This will soften the complexion which is being abused by your light source and bring the focus onto those beautiful eyes.
Really great idea, just need some more work. 5