Sounds like her family is worried about any changes to her will.Money makes people behave like animals.
She wouldn’t have to change her will, which would include language about required mental competency. Historically, a legal marriage automatically put the spouse in a beneficiary position, typically 1/3 of the estate (curtsy/dower rights).
In recent decades, many states have eliminated that right, but it could be that (if that is Mr. Harrison’s goal) he is not aware of its elimination, IF, in fact, VA is a state that has eliminated dower rights.
Yep. Some of the nastiest intra family battles will be over who gets grandma’s money.