LW says they really want their daughter to "find a partner who has a decent relationship with his family." In other words, they want her to find a man whose parents were not jerks who alienated him. But if they're worried that their grandchildren might have grandparents who are bad examples of parenting? Who are jerks with bad values who alienated their kids? They should look to the beam in their own eye, to use a religious metaphor they might not like.