Welcome, from another Sooner. I read your post....and noticed, you haven't mentioned anything about MC. Would she consider it? For that matter...would you?
I've had a HUGE revelation in my M with my H that prompted a pretty lengthy discussion with our C (one on one) about how people perceive R's once they marry and have a family. It happens at times with men that there is sometimes a shift in how they view their W after they have children.....they view them in a very motherly fashion, and the R can change greatly. Like in my M....My H and I had a different R prior to me giving birth to our S. After I had our S my H's perception of me changed....I became mother/wife.....I was no longer lover/girlfriend.....and was treated very differently. I can go more into depth on this if you want...but basically it's the whore/madonna thing.
While talking with our C about my H's perception of me and how wrong it was....she mentioned that sometimes, women do the same thing. Although it's not so much their perception of their H changes.....but their perception of the R as a whole and their role in it changes. I'm wondering if this isn't the case with your W. You know...once she had the baby...she became wife/mother, and the role of lover fell by the wayside.
If this is the case with your W a good MC can help her see that there is still lots of room in her mother/wife role for her to be your lover too.
I obviously don't know for sure that this is the case with your W, but since she was at one time very sexual with you and did behave quite differently I do wonder if this could be the case with her.
Oh, it would also be helpful to know what you've said to her to broach this problem in your M.