I know I am probably going to get bashed by the other posters for this, and I wouldn't even comment if I didn't think that this piece was worth the effort. However, if you don't mind... I have two very minor suggestions to what I think would enhance this otherwise INCREDIBLE digital artwork of yours.
1) I think the philtrum (place between the nose and upper lip) is too pronounced and should be toned down slightly so as not to draw the viewer's eye to that one spot. It's distracting to the rest of her face.
2) The philtrum dips too low into the upper lip making the lip too thin, as though skin is hanging over the lip. I think painting the pinkness of the lip upward slightly would completely enhance the overall effect of the work.
Other than that, I would say your artwork is flawless. I am very impressed and wish that I had your talent. Thank you so much for sharing your artwork with the community!