M.D.
Did the fever break? If so, I wouldn't worry. It usually takes the body 7-10 days to clear a virus.
To me, the most telling sign is how she is acting. If she's eating and drinking and has some energy, then I'd give it more time. If the fever is still high, or if she is really lethargic or refusing to eat or drink, then I'd call the ped again.
Also, I'm assuming that you are talking about a child at least 6 months old. If it's a newborn (less than 6 months old), then don't wait.