for a rabies shot to be legal and effective the dog needs ONE shot as a puppy, ONE shot ONE year later and then boosters as your state requires (1,2,3 years- each state is different) for you to say she "had it as a puppy" tells me she is NOT properly vaccinated
Bites from other rabid animals are definitely not always visible. I do definitely agree that it is a good idea to get her vaccinations up to date and you are legally required to have dogs vaccinated against rabies. Dogs should have up to date rabies (differs depending on state) and a yearly Distemper shot. Both rabies and distemper are easily transmissible and deadly. If she has not had a yearly distemper vaccination, she will need a booster 2-4 weeks after the first.
Other optional vaccines depending on your area include leptospirosis and Lyme. If she comes in contact with other dogs (dog park. Kennel, etc) she should also have a bordetella vaccine.
Another note is that rabies is spread by saliva, but all it takes for transmission is a cut on the hand and infected saliva to get in it. You don't necessarily have to be bit.
I know people don't always have the money for vet care, but there are often free sources for rabies shots that people can check into.