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.
This sounds awful … Elderly lady euthanised against her will in Canada


