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Shaking is often a symptom of pain so you will need to see the vet to find out the case.
Since she's shaking when she eats, I would be concerned about a reflux problem that might be affecting her.
Because she is also having trouble jumping on the sofa, she might be experiencing some pain from a back injury or other trauma that you are not aware of. Until you can see the vet, I suggest that you place boxes or footstools in front of the bed or couch so that she can climb instead of jump.
Any time that pain lasts for more than 48 hours, a vet visit is needed.
Let me know if you still have questions.