Hello! This is looking great, and I am loving the colors on her face. There is a few things to note however.
First, the neck is a bit long and it goes far too much to the left. Think about the connection of neck and torso! in this picture, there should be some more mass on her back to show that she indeed has a back, but as it stands; its almost as if she has no torso.
Secondly, although the face is beautifully rendered, you should get some reference for your skulls on her shoulderpads! Skulls are fun to make, and are all about expressing shape. Try to look at some and draw out the shapes before rendering them on her armor. Besides that, her thumb looks a bit weird due to the armor above. Remember, armor has thickness and make sure to express that! I can't say much about hair, as I'm not very good with it, but I also suggest trying to sketch out the feathers which are under her shoulders, otherwise they'll just look like clumps of paint!
Anyway, lovely painting. I really like the calming colors which only compliments and brings attention to her face. Good job ~