She's worried that we don't have enough in common to sustain us after the kids leave. I'm a little worried about that too; it seems like right now if we don't talk about our R, we don't have much to talk about.
I did not suffer the empty nest syndrome. My H and I had had someone living in the house with us since the day we were M, so to finally have just the two of us was wonderful. We loved it! It just didn't last very long. Kids just leave home, go multiply and come back with additions.
Since you can presently recognize the difficulty that could be in the future, which is finding something in common apart from the kids and having a R talk.......now is the time to begin changing that direction. Find something you both love doing as a hobby, fun activity, project, volunteering, etc.
She's not helping herself by worrying about these things in the future, however, it is part of that filtering she has to do. I honestly don't know how you stay as patient as you are with her. It would drive me crazy to hear that same old tune playing over and over.
She has to actually make some effort, herself, in this MR. It's as if she is just there pondering over the same old issues and looking at you to "prove" to her this can work. You must feel like a defense attorney at trial.
To her, she probably feels she is doing all she can at the moment. I know that's how I felt. And also, I have to remember we are just hearing your side of it. You are doing good. Just steer away from those R talks.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!