Very nice! You're really nailing the values here.
Hair is really hard, kudos for picking something extra difficult to try. I think you're right, the hair does look a bit more messy than curly. I would say you've gone more for strands rather than the coils you were after. You've got good tones on the earring, making it look really rounded, but I think the hair might look more coily if you applied the same technique for the hair, as in treating each "strand" as a rounded loop, just like with the earring. AKA, each coil has a dark side and a light side.
All in all, this is a really cool study, it looks like you really pushed yourself and learned a lot! Well done!