Apologies for the unprompted feedback.
I couldn't help but notice your shading didn't match the planes of the face. I wasn't sure what direction your light was actually intended to come from so I made these two different examples. A few things to keep in mind is that eye ball are spherical and will catch light even if surrounded by shadow. A 2nd thing is the lips, they way they sit on the face, the upper lip will generally be bast in shadow, while the underlip will catch light (if the light source is positioned above the character.)
Another thing I like to play with it how the nose also cast a shadow on the face. You can create this little triangle of light (in the style of Rembrandt) on the opposite side of the face.
