I'm so sorry that your daughter is in such discomfort, and that it is so worrisome.
How high is your daughter's fever? Did your doctor's office give you an idea of how high it could go before they would want to see her again?
I am concerned that she is having difficulty breathing. Did you tell your doctor this also?
Does she have a rash anywhere?
I know it's hard to get someone to take in liquids when their throat hurts so badly. Do popsicles help?
Yes, viruses are the most common cause of pharyngitis. A virus CAN take 10-14 days to clear -- think about a flu or a common cold -- but it's not necessarily going to take that long.
I understand your concern. And you're doing exactly right to worry about the escalation of symptoms and whether your daughter needs to be seen again. As we go into the weekend, do you have clear instructions from your daughter's doctor on what to watch for and when you might need to take her to the ER or an urgent care facility?