Thanks Tia. Your point about me asking for advice as a sign that I may not be as ready as I thought I was has really inspired me to reflect on this some more. I am more at peace than a few days ago, but am still feeling uncertain about whether what I'm feeling is a temporary and "normal" part of losing a marriage, or holding on for something because there remains a part of me that still believes in our relationship. The D was her idea, and when she asked for it I was at a point where I felt that continuing to hold out for some willingness from her to work on our challenges was now pointless.
I still haven't seen any behavior change since she asked for the D. two months ago; let me add that we don't live together, and haven't for nearly eight months. She's not indicated a willingness to talk about the R, or go to counseling, etc. I haven't asked her to do either of those, however. All summer and fall I signaled a willingness to talk whenever she wanted, and she never took the offer.
She doesn't seem to be running headlong into the D, however. So, that has me wondering if I and she really do want this. At the same time, I am fully aware that there could be other explanations for what is (not) happening here. I learned this summer about seeing what we want to see in life, and how that often leads to incorrect answers, so maybe this is another case of that. Ah, the tangled emotional and intellectual webs we can weave out of these situations!