If she isn't having any other symptoms and seems comfortable, I would not worry too much. Keep an eye on it, give her lots of liquids (because with less fluids, a fever tends to rise thus making them not want to drink and causing dehydration, and thus causing the fever to rise), and see how she does. Her body is obviously fighting something but without other symptoms, it is impossible for you to know what it is (sure a doctor could speculate and treat). As long as she is comfortable and the fever is under control, I would not stress...her body is working properly.
My daughter never pulls on her ear or runs a fever with her ear infections. It's not uncommon to be surprised to find she has one.
If she is still running the fever on Friday morning I would get her checked out before the holiday weekend.