I'm obligued to give you proper critique, then.
I could point many things, about the ligths and the details of sweater, but since is a unfinished piece, I can't tell if where aware, or you did'nt get to that part, so I only will focus in the face
About the face: the eyes are very different from the sourse image, the eyes from the sourse are kind of absent minded, she looking directly but she is'nt aware about you, in contrast, with your drawing, the eyes are looking directly at the "camera" and she seems kind of aware of a presence.
Look closely, the curve of the eyeslahes and position of the iris and the ligths.
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the mouth is a bit small, but I guess that is a stylistic choice, however the expression should'n be sadness, I think that girl the photo is reflexive.
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Asian girls faces, are like doll's, smooth sking and no prominent features, so the shadows should be more ligth,
I tried painting over the shadows with adyacent hightligths, with a mediym opacity/ligth flow brush
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I hope you finish this piece, it's going to look great!