My 7month old female cat isnt eating or drinking, what should i do?

Did you change her food, or give her something that she is not used to having? She could have an upset tummy. Or she on her own may have eaten something she shouldn't have. I would take her to the vet if she isn't eatingor drinking. Kittens can get dehydrated very quickly and that can be fatal. If the vet finds that she is ok then he can give her the shots that she needs anyway and kill 2 birds with one stone.