Hope you don't mind me giving you my 2 cents.
The mouth is open a lot wider, when I draw an imaginary line in the ref from the corners of her mouth to her eyes, they end up somewhere around the pupils. If I do that in your drawing, the lines line up with the corners of her nose/inside of her eyes. Quite a difference.

Her nose is pointier, and the shadows on her cheeks are darker.

Otherwise, good job, I recognized her, well I knew which Sarah you meant. :D

She's a pretty girl, but I cringe when she is on tv. Get embarrassed by proxy and that is not easy to do, I'm used to a lot.

If you add me i'll help you finish it off, jk :p Yea the corner's of the mouth should line up with the inside of the pupil's and the end of the nose should be wider, there's other stuff but there the main thing's that i can see.

ok, thank you three. I will to fix her, and than flubbles could write again all the other wrongs he detects :)