I don't see anything really egregious in what you did or said. You let her be the one to initiate. However, I do have to warn you.
I've been through 2 EAs of my W's. In both cases, after the EA ended she was inconsolable. It wasn't because she was sorry it happened. It wasn't because she felt bad for what she did to me or to our family. In both cases she was mourning the loss of the R with the OM. I know you think she is showing remorse for the EA (the EAs in your case). She is not. She is sorry she got caught and she is grieving the loss of the OM. It is a very difficult thing to watch, to know your W is pining for another guy even when the EA has blown up and has no way of moving forward.
I would also caution you that what she has admitted to is likely not the whole truth. Rarely do people in affairs just come forward with the details of the affair. They will almost always water it down and make seem more harmless than it was. In my W's case, the only reason neither EA had gone to a full blown PA was because of the distance between her and the OM. The first one was in our state, but over an hour away (and married with his own family). The second was several states away (and a complete loser with no money to make a trip). My W admitted to some inappropriate sexual talk in the first EA. I never knew if there had been more than that, though it was before digital photography was pervasive so I don't think it got any further than that. In the second EA, she once again admitted to some inappropriate sexual talk (even though the chats I discovered eluded to pictures being sent). I found later that she had in fact taken and sent him nude photos.
We have a saying around here: Believe nothing they say and only half of what they do. I would take her admission with a huge grain of salt.
But your approach is right. You need to GAL, 180 and continue to learn and employee healthy detachment (self-differentiation in marriage). I like that you told her your focus was on you. Now just follow through with action! LBS and WAS are similar in that they often will say and do not! ACTIONS not WORDS. So be sure to follow through.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018