If she is still shaking after you wrap a blanket around her, sounds like it isn't because she is cold. Also, if she stops shaking after you feed her, I would be inclined to think she is feeling hunger/hypoglycemia. Does she ever throw up bile in the morning?
I would try making sure she has a little something in between meals. Teddy was a very skinny pup with a fast metabolism. He needed more than his 3 meals a day, but we couldn't free feed him with Max. We give him a kibble or two as rewards for potty breaks, tricks, fixing his hair, and after an outing. Having these little extras throughout the day help him.
__________________ Kristin, Max and Teddy  |