Swelling is a sign that there is absolutely something wrong and most
swelling is accompanied by some degree of pain, so
in light of this, I would get her to an emergency vet this afternoon so that she doesn't have to be in a lot of discomfort until your regular vet opens in the morning. Dogs and cats are very stoic and can hide TREMENDOUS amounts of pain, so just because she's not whimpering of crying outright doesn't mean she's not miserable.