It is a principle thing.Her kids act like she cut them out completely. I bet if she left a chunk of money to some random charity, they wouldnt be complaining.
If he's making her happy in her late years of life and she wants to provide him some security after she's gone, so be it.
You better believe that if some Jr. set his sights on my mum, he's going to meet the bottom of my timbs and the bottom of a river if he doesn't take to the warning.