Texas intestate law question

Hello. I am trying to figure out who owns the minerals after a widow, Linda, died yr. 1936 without a Will. She was the sole owner of the minerals and had only one child - a son, Ed, who also predeceased her. Ed’s wife predeceased him. Ed had one child, Sam, but his probated Will gives everything to a charity. Who owns the minerals? The charity or Sam? A good landman told me it depends on whether Ed’s probate is open or closed. If closed, it goes by descent and distribution (to grandchild, Sam). If open, it goes by the Will (to charity). I figured I’d get more than one opinion on this. Thanks for your help.