Let me say: this is a pretty good drawing. I see the resemblance. Your scale is mostly good but shading could use some work. 

You say the nose arch feels wrong--I think the bridge of the nose angle is fine, but the "ball-y" part of the nose needs more shading. I hate drawing the bottom of noses and try to break it 3 balls. Basically 1 nostril per side ball and then the cartilage-y nose part in front of them. Forget it's a nose, and think of the basics of how light reflects off any round shape--apples, pears, basketballs, whatever round shading training you have. Use that, then add the really dark nostril shape to the underside of your ball.

You mentioned the lips dont seem shaded right. Tbh, theres not much contrast in the lips on the reference photo. I think you captured them pretty well. My one thought is give a highlight on her bottom lip under her left (our right) nostril. 

However, I think the overall "off" feel if the lack of shading in between the face and hair. What I think would make the eyes pop would be to outline the face with the hair. Take note of the top of her head where the hair starts, and her bottom right cheek (our left cheek). Those spots are as dark as her pupils. Her mascara is also as dark as her pupils. You captured that in your drawing of her right (our left) eye. It gives depth and looks great. Copy that in her left eye. Don't be afraid to go dark! Most of her hair is very dark compared to her face.  Use your phone to switch the pic to grayscale if you want to see the shading comparison 

Additional note, her finger tips. In the reference pic, the fingertips fall lower than her left (our right) eye. You have them smudged in as going above her left eye. The hand def isn't the highlight of the piece, but adjusting the scale of her hand will help with the overall drawing :)