A family in our neighborhood had a son & daughter. Daughter ran off with a no-good right after she graduated from high school; family didn't hear from her for 20 years or more. Son stayed home, farmed their 320 acres and took care of the parents.
They passed away in their late 80's - and left half of everything to the daughter! Son couldn't make a living on 160 acres he had left. The injustice of it all ate on him and he hanged himself in the barn a year later.
When someone takes care of the parents alone; that person should inherit the bulk of the estate. I made sure that my younger brother inherited the land when the folks passed away, as he took care of Mom for 15 years after Dad passed away.