This has happened to me twice, with sons not daughters. I have just listened, reassured them that I will help in any way i can. I never said anything about my DiLs as. I was always aware that they might get back together.
With my eldest was glad that he was out of a dreadful relationship, but I am very sad about the youngest.
All you can do is give as much support as you can.
Are there any current ads that make you laugh?
Do you have any favourite relaxing TV series or films?
, and I made the mistake of telling him some time later.