Unless you live with them, I think it’s impossible for you to judge. You see snapshots of their lives only, and parents often are more on edge around their own parents for fear their parenting is being judged. Maybe your DD panics about them playing up when you are there so shouts etc.
Unless you have genuine abuse/neglect/welfare concerns, leave it be.
How does a 'lived experience' differ from an 'experience'?
The King is to resume some duties.