She could just be excited to see you since its just lasting 15 minutes. Shaking can also be a sign of pain, maybe a tummy ache from just eating then jumping & playing on a full belly. So many different reasons...But if you are in doubt I would take her to the vet if thats what your gut is telling you. But if she is wagging her little tale , jumping & wiggling all oround when she sees you I would think she is getting a little over excited. My girl shakes when I take her out, even though she begs to go, she will shake for a few minutes when we get in the car, then stop, a few when we get out-any new enviroment for just a few minutes then shes fine. In time I think she will come out of it. She was kept in a kitchen & a play pen by her breeder for 11months of her life, now w/me she has free run of the house, umps on & off everything-she's well on her way to normalsy
Good luck