is this supposed to be a remake of that boxxy head?
if so there's a few things that need fixed; Everything.
the hair is pixelated, make it smooth by using the pen tool.
the skin color is too dark, the color of skin in the head jibailanjiao posted would work perfectly.
the "patch" over her mouth... just redo it. it's shaded as if it were hair.
if this is not a boxxy head remake read below, if not, skip to the bottom.
Your head closely resembles the boxxy head, so my appologies for assuming it was. Having said that, everything I said above still stands true for the texture you're trying to create.
Sorry for a bit of harsh criticism, but if you make the corrections, you could have a real masterpiece on your hands.