Hi 2lt, I'm sorry to read this. Your W is WW at this time for sure. She's a bit like my H - he checked out of the M and started asking OPs on dates (without ever saying he'd become unhappy in our M.)
I agree your plan sounds good. You are having an initial reaction, and your feelings about everything could change in time. Best to allow yourself that time and make sure you have no regrets. She may be completely 'done' with the M right now, but that may not always be the case of course - though you are right not to try and convince her of anything.
I can appreciate how hurt your must feel. It's worth recognising that she is probably also doing this from a place of hurt (albeit buried under layers of rebellion, entitlement etc. Just now.) She is seeking affirmation or highs or whatever in such places and is doing this 'for herself' rather than 'to you.' If you can remember that it may help.
In time you may decide this is a deal breaker, and time will tell. If it is, you can make your own plans to resolve things, heal and move on. However, I don't think it's time to go there just yet.
Do take care, and I'm sorry for your pain just now xx
T 13 M 7 Me 48 H 46 SS 15 BD 7.14 PA D final 5.16 (H filed)
We receive & we lose, and must try to achieve gratitude & embrace with whole hearts whatever of life that remains after the losses - Dubus