Okay, I read your thread, and I see where you are getting DB coaching and were told your W is a WAW.
As of yet, MWD has not separated the Walk-Away Wife and the Wayward Wife. The term "wayward wife" is not used in her books (that I read). I started a thread about wayward wives, b/c we had some ladies who suffered from abuse in the MR. Some confusion about being a WAW when they were actually getting out for safety reasons, helped me to decide to post the threads. I've been here since 2007 and I saw right away that there were differences in a wayward wife and the WAW. There are only a couple of things I respecfully disagree with MWD, and it is b/c you can't play BFF with your WW before reconciling the MR. You can't nice her back.
From what I have observed during my time here, the majority of H's who join the board seem to have nice guy tendencies. It has been astonishing to see this, but it makes so much sense that a man with NGS would have a wayward wife! If you want to read my thoughts about it, I have a thread about it. The first link to the first one is in Cadet's welcoming post.
If your W is experiencing hormone imbalance (which doesn't mean she is going through the change), it could certainly add to her emotional/mental state of unhappiness and confusion. However, I would not go as far as to say that hormones are the only cause for your W's behavior. I only mention it for your sake. Women are very sensitive to their H suggesting they go get their female issues fixed.
Without more information, IDK if she could be classified as having a MLC, like we often see in women who suffered a traumatic experience when they were growing up. Sometimes, the MLC is linked to psychological issues that were never resolved. Then later in their adult years, something happens to trigger those unresolved issues. IMHO, it is more complicated than her just dreading to see that 50th birthday roll around.
For now, my suggestion is to read my threads about H's who have a WW, and see if it looks like your W......at least the first one, if you are interested.
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!