This is very lovely. I love how you did her hair and clothing, it has got a lot of volume and flow. Her headpiece is stunning - the earring maybe a bit stiff, but everything so very very delicate!
Her face is simply brilliant - the highlights, the colours, the expression, your overall technique. Could it be that her right shoulder (that we see left) is a bit off? Or is it just the pose? The lighting on the skin is beautiful, even though I feel you could have used less yellow and more violet/red and white. But it contrasts nicely with the background this way. The background itself is simply great. The amount of texture is just right, no empty spaces - and those tiny snowflakes are so gorgeous.
Too bad the blue-green doesn't scan well, but it is awe-inspiring as it is!