helpme, you are doing great! Don't stop now. You are being kind, but firm. Remember, this is what SHE asked for, not you. Feel free to remind her of that next time, and to remind her that you are still open to R IF she is willing to fully commit back to the marriage.
And yes, DBing has a profound effect, most of the time, on the WAS. My W was the same way. She was cold, almost cruel, as long as I was holding on for dear life. As soon as I started to taking the same steps you took (GAL and detachment) she suddenly was showing emotion and expressing concern. Where was that before? Well, when she felt in 100% control she didn't need to be emotional and concerned. As soon as I started taking power back, her emotions and concern came pouring out. As did doubt, after he being so sure, that she wanted out of the marriage.
Denying seeing someone is fine at some point. But still be coy about where you are going and what you are doing. When she makes comments about you seeing someone, laugh it off and say "I am not seeing anyone." Remember, upbeat, cheerful, happy, fulfilled, pleased. But let her start the conversations, and then stick to validating her feelings. One of my favorites is "based on having just gone through it with you, if I were seeing someone I could understand how it would make you feel". Remember, do what works! Stop doing things that do not work.
Also, the doubts you expressed. "Is it driving her closer to him, etc". We all have those doubts. Prior to last week you weren't DBing....was she moving closer or further away from him? Do not let your doubts submarine your progress. We all come up with reasons that DBing can't work for us. Just remember, progress in DBing is hard fought. Losing ground is very easy to do. Each slip up could take weeks to overcome. So be as consistent as humanly possible in DBing. You are already seeing it yield fruit. DO you really think watching TV in the other room would prevent her from jumping over to WhatsApp and chatting up OM?
M(51), W(52),D(16) M-20, T-23 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018