We've seen this reluctancy in truly recommitting back to the marriage after an affair before from WASs. Almost always they are biding their time until the OP has a change of heart, or OM2 comes along. WW in particular have a way of attracting no end of losers. It's a sad reality whether she's actively on the prowl or not.
The good news is that none of it matters. You just keep DBing. Focus completely off of her. Look up "self differentiation in marriage". That's your new normal.
I have been reading up on Self-Differentiation. The first step is to be highly self-aware IMHO - something that I am still working on. She has no one to help her - her close confidant friends are obviously in a faux protective mode, her brother & mom aren't going to give her any good advice about MR or self-improvement and her IC is still the same one who aided her towards BD. She does not have the personality type to forget, or forgive - she tends to do the opposite, which is to write vicious messages (mostly on grievances that make no sense to me) and read them later to keep them top of mind as if they are trophies she should not let go. She has in fact told me that she wants to 'forget' and 'move on' but I doubt her intentions are sincere. Even so, she is still putting in material actions to improve the relationship, like cooking sometimes, random cuddling/kissing, trying to discuss day-to-day things, planning dates, etc. These material actions are a step in the right direction, but their efficacy is limited IMHO because of unresolved deep-lying issues.