BM, well done on most fronts. The only thing I would caution you on is reading too much into the positive aspects of your interaction, and forming expectations. The reason these sitches are so confusing, especially for the LBH, is that the WW, as sandi points out, wants the best of both worlds. They want the faithful H that is there helping with the house and the kids and the finances. AND they want their "sleep with who I want", GGW, partying, completely free to do what I want, wayward lifestyle too. This board is riddled with LBH in this situation.
So yeah, she sees you, she knows you've made a lot of positive changes, it is attractive, but she still has this wayward streak that she isn't quite ready to give up. That was the exact purpose of her monogamous. "I might be open to reconciliation if I still get to sleep with other people!" Cake....and eat it too. I can remember early in my sitch when my W made a comment about how we might still be able to make it work if she slept in a different bed. Essentially she was saying that she wanted her house and family, but she didn't want ME as a lover.
So you did the right thing not to jump at her talking about a future R. She probably thought you were still desperate enough that you'd be agreeable to any conditions as long as you were still with her.
The looking good was great. But what really made you attractive to her was standing up for yourself and NOT being desperate enough to just agree to anything she said. That is going to be what sticks in her head the most. Whether or not you end up back together, she will RESPECT you now. The fact she even went there with the monogamy comment showed a lack of respect. You took that respect back by saying that was non-negotiable.
One last word of caution, and it goes along with the earlier caution, don't let yourself be manipulated. I just had a couple of exchanges yesterday with LBSs that thought DBing had worked to get their WASs interested, only to see them retreat as soon as they stopped DBing and started pursuing.
DO NOT START PURSUING. I know you TOLD her you wouldn't, but continue to SHOW her you won't. Don't initiate any communication that isn't strictly about logistics around your S. Answer her questions with as few as words as necessary. Be the one to end communications. Most importantly, when she texts you messages that are informational, DO NOT RESPOND. If she later questions why you "ignored" her, just tell her the text didn't require a response.
You are LRT. Your sitch meets the specific circumstances where LRT should be employed. Be consistent.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018