This is AMAZING. At first glance, I was halfway convinced it was a photo! Honestly, I can't find anything that needs improvement here, your work has such great quality to it, so I gave you full marks for everything. Anyways, I'll just babble about my favorite parts of the piece!
First off, the overall colour scheme is absolutely gorgeous. The red really captures the eye's attention, and is also drawn in by the pretty glittery effect on the girl's hair as well as the red cloth and her lips. The black background creates a wonderful contrast too with her skin, so it's quite eye catching.
Your attention to detail here is awesome! Everything is so real and lifelike, I love it! The one part I particularly enjoy is the shadows around the girl's eyes. Very soft and real looking, not to mention that the proportions of her face and upper body are great too. The transition of her hair to the glitter is quite smooth and it blends well with the rest of the piece. Again, fantastic, beautiful job you've done here.
I like the use of color, balance of image and sense of movement - you gave a very just treatment of the photograph. Also, this is very, very well executed. I could only hope to paint this well some far off day. Keep up the great work!
I don't like as much the "breakup" around the lower half of her face - I see where you were going with it, and it's a great idea - but with all the realism in the rest of the fabric and skin folds, hair and so on, the disintegration seems just too regular for me. In my mind, people don't shatter and crumble so smoothly, odd as it is to think about.