It sounds like she has a bacterial infection. It could be spread from a sinus infection. Either way, she needs an antibiotic. Until you can get to a doctor, you can try using some warm compresses and see if that helps with the swelling.
Hope this helps.
It depends on what time it is. You can wait a few hours. But if its 8 hours or more before the offices open, then you should take her to the hospital (especially if it is getting worse). Infections in children can be very unpredictable.