I have one on either side, with one side larger than the other. They don't really hurt, but sometimes, they do. I would bring up the issue, however, with your daughter's doctor, so they can run some tests and check it out. Make sure it isn't something more serious.
My son had several at different times when he was younger, but doesnt get them now (he is 10) , but the doctor said they were just swollen lymphnodes and its normal, they will go away on their own. i wouldn't hesitate to make an appointment with your doctor though.
It could be a prominent lymph node which could be serious or not. You should get that checked out before trying to do anything with it. You should have her pediatrician check it.