Really nice job on this! Your painting is really great. The only areas i see that can be improved are the values. I quickly did a comparison to show you here. There are actually no white highlights in the reference image at all, but maybe you brightened them on purpose?
I think if they were brightened on purpose though, there would be more areas of stronger highlights on the cloth and armor as well. Not just the skin.
Value comparison - original is on the right

Very quick adjustment to show you what i mean
