Remember...look forward, not back. The past can't be undone, but the present always looks ugly when our glasses are made of the past. When the past makes the future, it looks that much more ugly.
Let the anger go.
IF she truly wants to give the M a chance, it won't last long if all she sees is bitterness and a lack of forgivness. IF things work out, she will apologize in time. She will.
IF she's saving face, only God will truly know. But, even still, the efforts to save face may lead to honest work on the marriage. Maybe something will come out that flips her views.
Have you watched the videos from DB on youtube. Along with Retrouvaille, I found them helpful in 'convincing' me that I need to build a NEW marriage with my wife that is not controlled buy judgments from past meanness (etc) of my wife.
I am VERY excited for you IDL. In one day, you may have a terrible or wonderful experience. But...it is moving forward.
Pray and thank God alone for the chance. Sleep well. Expect no miracles but have the smile that said you are about to get one. Your children will be very proud of your efforts years from now.