Once again it's the forehead that bothers me. It's not quite high enough. There is a little bit of a ridge between the skin, and her hair, that you have left out, little bit of a bump at the very top of her face that you have smoothed over too much. It makes her look less intelligent. It's her frontal lobe that you have minimized. She needs that.
Also the top of her head (her hair) needs to be just a bit higher I think. If you have measured, and found the face to be correct, then perhaps her eyes are a little too high on her face. That would make the forehead a little too small. I looked again and I think that the forehead just needs to be a little more square rather than egg shaped.
Does anyone else see this, or is it my imagination?
Color has never been my strong point. I have worked on that color paper. The one horizontal Baby Jesus drawing on my web page is on that paper. I now work on gray paper because I had trouble with it. Your portrait here looks a little cold to me. I would try a little Daveys Gray (W&N) in the shadows, and a little pale Raw Sienna in the light parts of the skin to warm it up. Just try a little bit and see if it works at all. Another good color might be a very pale burnt umber (W&N) rather that that purplish red that I see. A little bit of that is ok, but it's quite cold and strong.
These are just suggestions. If It doesn't work, don't do it.
About the background, I think that you might be able to use the window to balance this composition. It becomes part of the composition in the photo. Do a small sketch, about 4x5, with a pencil, and see how it works, before you make your decision.
It will look better also when you crop the paper that is above her head. That empty space above her head is very distracting. If I am not going to use all of my paper, I always draw a line around the space that I will be using. Your negative space is as important as the space that you fill.