Doing the "right thing" is a step in the right direction. In other words, for some WAW's who are in an A, they just have to make a decision to do what's right....even though her emotions may not be cooperating with that decision at the time. But it's a start.
If I could talk to her, I would tell her that if she tries to make her choice based on her feelings, she will experience a lot of confusion. Naturally, we want to follow our hearts, but when one is involved with OP outside of the M, the heart can hold a lot of mixed emotions. Many people wait on the romantic or in-love feelings to guide them, but that can be very unwise for our future. That is one reason the spouse in an A has to "commit" to stay in the M. They should agree to the terms (within reason) of the betrayed spouse and understand they will have to really put forth a lot of effort to prove themselves to their spouse. Commitment and work come first, and then feelings will come later.
In other words, she doesn't have to feel happy about ending the A and staying in the M....for this to succeed. And the reality is, you probably do not need to expect her to show a lot of happiness in the beginning of piecing back the MR. That statement is probably hard for you to swallow, but it goes along with what I've said about how she will experience withdrawal & depression when she drops OM. IMHO, She can't experience those feelings....while at the same time feeling a lot of happiness for her M and/or H. It's difficult for me to explain the emotions one feels while going through the transition. The betrayed H can experience offensives due to how his W feels about everything.
Usually piecing the M back together is hard work and takes longer than either spouse thought it would.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!