Your breed is prone to hypoglycemia which may lead to shaking/ tremors and lethargy if the blood sugar is low. These breeds need to eat throughout the day to maintain their blood sugar levels. Try putting a little pancake syrup on the gums and see if she peps up a bit.
The whimpering when trying to move could be a disc problem as toy breeds are affected by this. It can come on suddenly or slowly over time. What happens is the soft cushioning tissue of the disc becomes hardened and places pressure on the spinal cord. You may see lameness, lethargy, reluctance to move, climb stairs or play, and pain in the back or neck area. If it is severe the pup will yelp when touched or handled. Here is more on this.
This breed is also prone to luxating patellas which is a problem with the knee joint. This would cause pain or reluctance to move around.
Reasons for shaking and tremors: