This is definitely one of my favourite pieces of yours along with Grown together. And while I don't feel they could be further apart in there over all esthetic I can't help but feel the same amount of passion and intensity in both pieces. But onto the critic.
Composition in all regards excellent. Your placement of the figure and use of colour in the background moves your eye around nicely and keeps the picture moving nicely always giving your eye something to look at. The fact the her face is darker then the rest and more detailed draws your eye back again and again. Perfect execution.
Your color use is great. Very captivating and pleasing.
The only reason I put originality lower is because of the subject matter. But the execution is flawless. Honestly I don't know how one could make a portrait original anymore. So I'm not laying any fault at your feet for that. Besides who doesn't love painting females or looking at them. Or people in general. We are vain creatures.
Absolutely stunning work. I love it.