Has anyone supported an adult child through their marriage breakdown?

Has anyone supported their adult child through a marriage breakdown, when their own child is the instigator? There is no third-party involved. There are no children involved. The partner is much loved by me and is a wonderful person, an honourable person from a wonderful family. As the parent, I am enormously sad about this and struggling to come to terms with it. I will support my child wholeheartedly, but feel so sad for both of them. I would like to interact via PM rather than “publicly” on the website. I’m really only looking for people who have been in this position themselves.