I used to babysit and hour or so after school for my great nieces. The older one was attending a Lutheran school, and I would pick her up from there. Often she would share what she learned that day, including sometimes "Jesus Time" at school. I was a good listener and kept all opinions to myself. I limited my influencing to encouraging reading, sharing toys, being kind, making laughter, going to the potty, and not fighting.

Much depends on the family dynamic and the individuals.

My wife and I are careful not to undermine our daughter's parenting or her children's respect for her in any way, even though we disagree with some of her parenting decisions and priorities, and have some legitimate concerns around them. These are not questions about their basic safety or physical / mental health, it is around education and discipline and household priorities. But the thing is, as grandparents, those kind of things aren't our responsibility anyway. That cuts both ways: we don't have to worry about it, and have no right to meddle in it.

I really think you need more nuanced choices. & also it depends a lot on what your relatives are like. I would not even have left my kids alone with my parents, to begin with.

I have a wonderful niece (14 years old) with whom I text on a fairly regular basis. I told both her and her parents that the contents of our conversations are private UNLESS I feel that something she has told me is putting her in a dangerous situation -- in which case I will share with her parents. She is also free to disclose to them whatever she wishes. She has no living grandparents and I'm more than old enough to be someone's grandparent so I sort of play the role of surrogate. I absolutely think that kids need an adult who is not a parent in whom to confide if they wish. It can provide a different perspective on the situation.

I’m fortunate to have an incredibly close relationship with my boys. Family is great but ultimately they are my responsibility and they are aware of who they can and can’t trust( divorce does that).

This reeks of control. Do they need to know everything that everyone of their friends say too?

Helicopter parenting at it's finest. If you are worried about who is saying what to your spawn then you obviously feel like you are doing a lousy job at teaching them anything from values to "street smarts".

I met a woman the other day who was a HS friend of my friend. The woman, who we met in a Casino, talked about her kids (she was a bit old for kids). My friend told me they were her grand kids. Her kids were into drugs and so the grandmother got custody. I know this is common but if the mother failed the first time perhaps it's not in the best interests of the children to have her try again (but what can the state do)?

It may also depend a great deal on how "grown-up" the relative is.

Circumstances are everything.