Hi! Here's my paintover:
I hope my sketch helps explain what you could try doing with the anatomy and gesture- the way her hips and shoulders are aligned looks unnatural. Also, if someone's holding something in their hand, that will move the angle of the shoulder down as well. The way that you have her standing, especially in heels, looks kind of unstable too. Also watch out for tangents, her sword handle intersects with the edge of her skirt, and her sleeve goes right to the edge of the hilt part. Pick one to be overlapping the other, it'll create more depth and also make it less distracting.
In terms of colour and lighting, i think you need to consider your shadows more. The ones on her clothes are very dark, indicating that the light is very focused and/or not very bright, but the shadows on her face and body are barely there? Also if there's a reflective surface like the sword right next to a light, there should be a sharper highlight on it. I didn't have time to go in and paint over the face and hands in detail, but also remember that skin will show more of a red/pink colour at the edge where the light meets the shadow. There's a lot of opportunities to put more colour in the cheeks and nose and fingers, if you don't take them it can look kind of lifeless or flat.
Overall, try to use harder brushes when painting! I know everyone will tell you this, and it might look really bad when you start, but it'll help you learn.