My dog hasnt been eatting much and she always tired?

She may simply be going through a faze of laziness. All dogs do at some point. This can be down to breed, age, size and care. She could be pregnant but I doubt it as then she would probably eat more and be quite aggressive. So long as the dog is eating an drinking to maintain it's health then it should be fine. But you should take it to the vets just incase