Single parent dies. They have two children in their 60s. I'm using children in the broadest term here because obviously they are not children.
One of these has two children in their early 20s (their only grand children). The other "child" has none.
The child who has no children is pretty well off. The child with two children is not so well off (possibly because apparently it costs £180,000 per child to raise them from birth to 18).
The parent divides the will one third each to her two children, and one third for the grand children to be split 50/50 between them.
What do you think of that?