My Child Is 9 And Has What Appears To Be

My child is 9 and has what appears to be white crud on her tongue, a moderate fever off and on and she had a blister on her lip that is better but still sore. She was prescribed Augmentin. Should I ake her back to the doctors as she is till in a lot of pain and cannot eat anything. She will drink a little fluid. I have been giving her glucerna snack shakes as this is the only thing I can get her to drink besides a little water. She has been taking the medication since 6/29.