My daughter is 13 she was diagnosed with a sinus infection was prescribed amoxicillin she has taken it for five days and she's worse 100.0 fever.

Call in tomorrow. It sounds like your daughter may have a resistant germ and not be responsive to the medication. I would contact the physician who examined her to consider the possibility and make other treatment plans. There is also the possibility of a co-existing problem. Amoxicillin usually works but no med works every time.