We’re very lucky with our children, even though our daughter is currently living and working in New Zealand, she has remained close to us, much more so than when she was married. She’s now getting a divorce. We speak to her all the time and also the grandchildren. Our boys are both married, one with a child, and we see them regularly, get together regularly for meals, go out together a lot, have our grandson over a lot. We help them out a lot, my husband is always doing jobs for them and we did also in New Zealand when we were visiting our daughter for two months in the winter. That’s our family though but not all are the same. I love the way our family is and wouldn’t change it. We’ve had experience of control in a marriage in our family but that person is no longer part of the family.
Likewise I was close to my parents even though I had ups and downs with my mother. And we were close also, but probably a bit less so, to my parents in law. That’s who we are and I love it. But others are not so close and that’s fine too, so long as no one is being coercively controlled. That is crucial.
I don’t know how the OP can resolve the issues apart from maintaining a loving relationship with her son and daughter in law, but not asking for any information. It’s tricky though because she could then be accused of not being interested!