MY 23 year old daughter has a sore throat only on one side. She says she can see something white at the back of her throat. Could this be tonscils.

She really needs to see a doctor. It could be ulcerated tonsillitis, but since the pain and white stuff are on only one side -- usually both tonsils are affected. Not only will a doctor be able to diagnose (as you know, over the Internet it's impossible to do that), he will also be able to give her a prescription for antibiotics, if that is what she needs.