I don't like position of the nose in first picture. It should be more on right because is 3/4 view.
About hair.. headband is too tight (don't know different word to describe it) and that makes you head above forehead to small.. that automatically makes hair looks too small as well.
really quick edition to show you what i am talking about:
Red is how the head seems to look like
, green is how i think it should look like from this point of view.
If you were drawing hair considering head is like green lines, it would look just fine.
Other than that, very promising drawings