It would be helpful to know the context of the conversation between your W and mom and what kinds of things were actually talked about. It does sound like guilt driving her home, and like you said, it isn't an ideal way to get her to come back. I guess I would just do what you've been doing -- be that shoulder to lean on and cry on, hold her, listen and validate, empathize, etc. Maybe if she opens up enough you might consider mentioning your realization about the fun guy you used to be and how stuffy and frugal you became in recent years. Don't know how you can do that or if it the best thing to do, but I think it is worth consideration.
