My Mom had slight tremors in her hand tonight and then later her whole body was shaking. What's happening?

She was not cold. This is new. And what do I do? I called the on-call dr. No help. He said he "didn't know her and it could be a thousand things". I walked her to the bathroom and had to clean her up and her poop was green. This is new too. She had a good dinner of fish, fresh broccoli, potatoes so I don't think she was sick from the food. I put her to bed and she was shaking so bad. I just held her hand and stayed with her 'til she fell asleep. I will call her neurologist for appt. but that won't be 'til Monday. Any ideas of what I can be doing to help her and what your experience has been with this? She seems to be going another level downward...
cadams