I love it, for the following reasons, which all play off of one another beautifully:
1. Your girlfriend is striking in appearance.
2. The lighting creates great texture and mood.
3. The monochrome conversion makes the fades in the jacket pop...great job of highlighting texture (see also shirt and hair) while preserving her feminine beauty.
My only critique is a minor quibble, which relates to the aspect ratio, which appears to be straight out of camera. I personally would prefer an 8x10 crop (too much lower torso IMHO) or even a square crop.
I am undecided on the elbows, therefore their omission does not kill the photo for me, especially since every else is so strong. Bravo.