Finally, my elder sister and her husband didn't divorce. Her mother-in-law
comforted her, and she finally relented to maintain this relationship.
This makes it very awkward when we get along.
Most people still want to maintain peace, less disputes can get less trouble.
The last resort is to use a more intense method, but that is a waste of time
and effort.
For family atmosphere, I think they divorce is better. Otherwise,
it's annoying to be noisy all day long. But my elder sister will take care
of the child alone is more difficult and tired. And the child without a dad,
it is not a good thing for his growth.
How to do better, I really don't know. I can only continue to observe it.