Wow, 9 years of Belle being bad! Perhaps she acts that way because there are other animals around, to get extra attention. 9 years isn't too old to learn though, I wouldn't give up on disciplining but try another method. (I'm sure you tried it all but perhaps a behaviorist could understand the dog's actions and come up with a new solution to try.)

Do you give her extra attention when she is good and ignore her when she's bad? Does she get enough exercise?

I can't imagine a lab getting to the top of a microwave - Belle, if only you would put your energy and resourcefulness to good use!!