The mouth is crooked, it should be più aline with the crevice under the nose, which is also slanted slightly. Both of which should be parallel with the arch of the chin, so looking at it from my pov it looks like her face is sliding slightly. But the shading is off to a good start te should mostra più texture in the skin and shadow in the upper cheek bones. But the shape of the face is good, though I would use lighter lines so she would look più 3 dimensional. But over all it looks like your off to a good start!