My Daughter Has Had A Sore Throat For The Better

My daughter has had a sore throat for the better part of 3 months. I work in the lab at my hospital in town, and she was diagnosed with strep, and put on amoxicillin. After that, she was still not feeling well, ayd was put on another antibiotic, followed by another shortly after. She got put on the schedule to have her tonsils and adenoids removed on December 23rd. Today, she came home from visiting her grandparents over the weekend, and her tonsils are even larger than before, and she now also has a lymph node that is significantly larger as well. She had a low-grade temp of 99.6 tonight before bed. A little bit ago she came upstairs shivering. Expecting a high temp, I checked her, and it was 96.7. What could be causing this low temperature? Is it still wise to wait for Friday's surgery, or should I talk to the ENT office when they open?