Have you taken her to the vet, and how long have you had her? If there was a problem with her, the vet should have picked it up, if you took her, after you bought her. Other than that, she ay just be frightened and nervous because she's been taken away from her dam and litter. Did you buy her from a breeder, or a pet store? I would just keep paying lots of attention to her, and see if the shaking stops, but if you never took her for a well puppy check, I would do that right away.