My own dog was bitten by a dog whose vaccines were out of date. However, they were not far out of date (like a few months). Given that even a one year rabies lasts longer than a few months past the vaccination date, I wasn't worried. Rabies vaccines in the US are so good that the chances of a vaccinated dog contracting rabies is really really low.* Just make sure that you have proof from her vet (not from her) of her dog's vaccination status.
The vaccinated dog would probably have to be bitten by a small colony of bats while in a bat cave breathing in bat spit while bat menstruation gets sprinkled into into the cuts caused by the bats feeding on the dog, to get rabies while vaccinated. But seriously, I don't think there's been a case of rabies transmitted by a dog bite to a human in 30 years, and your dog's risk in this situation of being bitten by a rabid dog would be the same as if you had gotten bitten by the dog and your risk of contracting rabies is actually higher, since you're probably unvaccinated.