You're doing well! Learning how to draw a head, especially a realistic or semi realistic head, is definitely one of the most challenging things to learn in the beginning.
Here are some things I see that could use work:
Think of everything as 3D when drawing.
I think you're doing that to some extent with most of the drawing, but the eyes definitely just look 2D. When drawing the eyes, really try to think about how the skin is wrapping around it.
Both of her eyes are about the same size.
In reality yes they are probably the same size, but from this angle, the visible part of her eye will be slightly different in size.
- Overall proportional issues.
If we're going off the reference, I can see some issues with the general placement of some of the facial features like the mouth and left eye. And her jaw as well might be a bit too wide. I recommend going back to Marc's anatomy video about the head until you're confident enough to move on to the next step.
I hope this could be of help! I am not too great with criticism so please take what I say with a grain of salt. If other forum members see issues with what I've said, please correct me! I wish you luck with the rest of your art journey. You're making good steady progress.