this may sound like a stupid question, but has everyone noticed how quick vets are to prescribe antibiotics? Personally I hate killing off all the good gut bacteria in my dog unless I am forced to kicking and screamingMy female puppy had the same thing happen in her cheek after she was bitten in the face. The vet initially thought it was an infection developing despite antibiotics she was on... it got so large so quick that we were draining it daily for about a week. It finally stopped filling itself so much and slowly went away on its own.
I would just keep an eye on it and be sure it doesn't develop into an infection and I think she'll be fine.