Anyone else have such crooked relatives?

I know this sort of thing happens all the time, but I thought I'd see just how often. My wife's mom had 3 sisters. They were all raised together and for all appearances, got along well. Their parents couldn't afford a house and land of their own, so while still young and unmarried, the girls worked and gave a portion of their checks to the parents to pay for about 20 acres of land. The land was supposed to be divided among the sisters and 3 of them built houses on their part, leaving about 7 acres for the parents' home. That land was to be divided among the sisters after the parents died. A will was written to that effect and everything should have been settled in advance. Eventually one of them was appointed executor of the parents' estate some 15 years ago, and evidently she coerced her by then senile mother into changing the will so that her son got the house and land for 1/20 its value, about 30k, and the others get nothing. Now I know why her husband frequented the local cathouse