I am going to go against the advice of the rest of the board here and say there is no reason you "have to let them go" if you view them as family. I also come from an extremely broken and dysfunctional "family". W's family has said they will always view me as family - and they meant it.
IMO - I think it's a bit ridiculous to drop everyone because of something your W is doing and not you.
However, if you choose to keep them in your orbit, understand that your relationship with them will and must evolve. It will be less involved, and you will have to pull back quite a bit. I agree with ovrrnbw here - let W have her family first. They are her support during this.
No more R talks with them about you and W. Find a neutral sounding response with regards to how you communicate with them. "Yeah it's tough, but if it's ok I would rather not talk about this right now" is something I say now.
