Okay, sooo..
This is what I did so far. It's really important to have a ref picture because thinking out of your head will cause you to have a lot of mistakes. I say this because my teacher really drilled this into our heads for perspective. Also, refrain from rendering at all until you having everything to your liking, it'll save a lot of time (even if this is for your own pleasure) and it's a good thing to practice so you won't get too attached (in case something bad happens).
The eyes seem a little far apart. Because the face is turned, the farthest eye should be slightly disappearing behind the bridge of the nose. This is where ref would be helpful because it'll help you know how things looked turned. Unfortunately, the mouth is drawn flat, so you would..have..to fix that. (Sorry!)
The upper lip protrudes more than the bottom (even if the bottom is bigger), and my teacher described the corner of our lips as donuts. If you feel that area, they puff out, so as her face turns away from the light, you would see it puff out where as it looks flat. It's a good thing to touch your face in case you're struggling with something.
So, this pose isn't a profile shot, therefore the other nostril would still be seen but barely like how I badly put it in there. I drew in the neck how it'd be posed and I tilted the shoulders because I actually tried her position, and with her shoulders leveled with a tilted head is really uncomfortable. (Ref!)
I can help with shading too but it's like 5AM and I must sleep. I can explain more things when I come back too. Sorry for rushing!