Natacha, whadaaap!
I can't believe you took the effort in filling in THE REST of the paper!
I'd never have the patience.
As for the shading of the face... it's fairly good. Seems like you flexed your skills this time around, and I'm proud for you of that.
The lips look strange in a way. I think the middle of the top lip shouldn't have that wide of a curve as it does, and you should try to balance the thickness of it more evenly.
That's all I've got to say for now.
keep drawing!