My daughters face is swollen on one side?

It could very well be a tooth abscess that can cause an infection, and there's times you wouldn't even know you have it. There is not always pain when it happens. If you still have it after a few more days see a dentist. The same thing happen to me years ago, it was an infection in my gums and never knew i had it. Also try cold ice packs on the swollen area until you see a dentist.