Nice work for a 10-min drawing and I like it very much, however I still see some small problems that you may want to improve or fix.
1. From what I can see, it seems that you spent some of your time trying to add details on hair. I'm not saying it is wrong or you shouldn't do that, but as the chapter's name shown, the work should be more focused on face and expression. A few lines usually would be enough to build the shape. If the character has dark hair, just shade it.
2. I can see you draw out some muscles with solid lines, this is great and will help you build up a face in a short period of time. However, under the the skin of our faces we have muscle that rarely drawn out with solid lines (like muscles around our eyes), and it might help shape the face further or enhance the expressions if those muscles are drawn. You may want to try to use light shades to let an audience knows the muscles are there without break the whole atmosphere too much.
3. It may also be worth it to spend some time on adding details on character's lips.It might be helpful to take the texture of 3 different kinds of skin (normal skin, lip skin, and skin inside our mouth) and the shape (our lips is actually a thick, round, soft tissue that covers the front of our teeth ) in consideration when you draw it.
That's pretty much all feedback I can give for now, hope it will help and wish you success on your artist path/career. Also sorry about my poor English because I'm not a native speaker, I would be more than happy to provide further explanations or share more detail and tips if the need rises.
A big thank you for your very constructive answer that will allow me to take up this face otherwise.
I was desperate not to notice and was wondering if the site was dormant.
I have an English school and I use google translation. I hope that this translation is correct and that our English-speaking friends will be tolerant.
So I'll go back to work on facial expression.
See you soon !