It might also be that she set up trust funds for each of her children.....years ago and it’s just her personal estate left.
Could be.
Don’t get me wrong. I’m not hoping for drama and trauma, just noting that such usually happens when the rich and/or famous die and leave family behind.
And it could be that she was a true boomer and decided “hey, I got mine, screw all you!” like so many have taken to doing in their endless self worship.