Your W, like mine and most other WAW's relished the freedom from the pressures of her marriage and especially YOU that her A provided. Well, two things have changed. First and foremost, YOU have changed into someone who does not need to put pressure on someone else. You are a self-contained unit of happiness. You control your own emotions and let hers be free to exist. Tied into that is the fact that in her mind, since accepting the D as the ultimate outcome to all this, she is now free from pressure altogether even in the marriage she felt so trapped by. Since she clearly sees the D as a "get out of jail free card", she is just being a free woman, attracted to a free man. I think her actions show that she maybe recognizes this for herself and is afraid that if that divorce door is closed, then she will go back to being trapped. That would be why she keeps mentioning the divorce every once and awhile. She needs to remind everyone (you and her) that no matter how comfortable things get, her escape pod is still there and ready to launch her back into space the moment she starts feeling that old trapped feeling. Well, Frank, the good news is that she will never feel that feeling because of YOU again so unless she manufactures it in her own head, which is very possible still, she may continue to go down this road longer than she expects. She might end up where you are; a place with many roads and true freedom.
I don't know if any of this is the truth, but it is one theory that seems to fit your situation.