If your dog were an average size, you could try to hold her off food for one day and see how she does. It sounds like she was just excited. Since you mentioned she was tiny, however, you need to be more concerned. Your dog can become dehydrated and hypoglycemic more quickly than a larger dog. The safest thing to do would be to take her to your vet for an exam. If you cannot do so try to keep her calm and give her water slowly, as in ice cubes that she has to lick to drink.