Get Your Dog Care Questions Answered by Experts
Dogs will shake and shiver as a response to pain so you should take this pretty seriously.
I think that you need to return to your vet today to discuss your options, particularly since she is not eating well.
Let me know if you still have questions.
If your vet suspects that your dog has a kidney problem, they usually base this on blood work and clinical findings.
I suggest that you take the vet's advice and get the second opinion.