I agree that you shouldn't cut someone out of your life because they won't do what you want them to, but again it sounds like we only have one side of the story from the son's perspective. Trust me, in my family, thank goodness not immediate, they cut people out of their lives right and left for foolish reasons IMO, and I usually take the side of the cuttee not cutter. But, I'm aware of the three sides of the situation.
I'll still go with holding off final judgement to see if future info on Irene comes out. A person lives 87 years, and I prefer to base my opinion on more than a few incidents in their life. For every down side presented of Irene, there seems to be a good side to match, just like the vast majority of us.