So as you are going forward with this I can point to regions that you want to stylize more to fit with the picture you are working from.
You are probably going to need to thin out the arms and lower the definition of the muscles on them.
The transition from the thighs to the butt should be smoothed out, the art seems to have a rather "meaty" thigh going on. If you want easy examples of a pleasant butt transition (because the concept art is clearly drawing a large amount of attention to it) look to bayonetta, there are plenty of images.
Simplify your knee and smooth out the calf muscle to match the style.
Push the forehead forward to create more of an orbital cavity for the eyes. If you have any side images of the art that might better dictate the style in that regard.
Keep at it and post some more progress, I look forward to seeing it finished.