Female (79) sudden shakes entire body. What should we look for?

Babalou's absolutely correct. You need to see a doctor, ASAP.

These are some things you can be prepared to tell the doctor.

1. When did these shakes start? How often do they occur? How long do they last?

2. What stops them or do they stop spontaneously?

3. What was she doing before they started?

4. What are her other medical conditions?

5. Are they total body "shakes", and shaking as if she's shivering, or are they more like seizures?

I think I would start with a neurologist, but if you have to go through any kind of referral from a primary care doctor, start there.

Don't wait; this should be addressed immediately.

Or, you could also take her to the ER the next time it happens.

We are NOT doctors, that should read

We are no doctors. You should call her doctor.