The hair, the blouse, and the background are beautifully done. But the face isn't quite right. The nose looks crooked and too long, and it seems to begin in the forehead. The mouth is too far down, it appears. Perhaps the face is too oblong. We are extremely sensitive to the proportions of the face, unlike the proportions of a tree. That's why it must be right, if you're not doing a Picasso.
It is good that you've used bluish tones on the face, but the strokes appear to have been randomly applied. Instead every stroke should emphasize the shape of the face. If this is done in a simple manner the paint layer won't look muddled, but rather radiate firmness. A painting should radiate resoluteness but not shakiness. You seem to have good artistic feeling, but you really need to sketch the face correctly first.