Avelox for resistant strep throat

My 15 yr daughter was diagnosed with strep throat after blood test. She took Zithromax for 5 day, didn't cure, took 5 more day Zithromax, tonsils still very large, visited with Dr and prescribed penicillin. After 4 days there was no improvement. Called Dr. office to say no improvement, they had us come in. Her regular doctor was on vacation for the week. So saw other Dr. in office. He prescribed Avelox, she's taken for 2 days. I just got on line and read the comments others have put in and am not sure I want to give her day 3 pill. Plan on calling the office and asking to speak with her regular Dr., I'm so concerned. What would you do?