And in seriousness, if I was her, I wouldn't cut Gaddy out entirely. If Gaddy has been a loyal help for the past 10 years, the moral thing to do is recognize that. Assuming Mae wakes up, I expect she's going to be a darned uncomfortable spot of trying to figure out which of her relatives is spinning the truth.
I would think she should make sure that Gaddy is out at least until such time as Gaddy can be removed from any position where she might try to get Grandma killed. Make her want to keep Grandma alive at least long enough that Grandma might decide she deserved some inheretance after all...