I just read your thread. You sound like such an amazing person. Don't be surprised about what she has done. It is part of the package. They all do it and yes, it can even get much worse.
I'm not saying stay or go. That is your decision.
She would not be in MLC if she was not lying, cheating, justifying, rationalizing, and defaming you.
All I know from reading your posts was that you were on the right track. You were doing beautifully and DBing perfectly. OM is clearly threatened by you. He is clearly someone way way way below you.
I JUST WANTED THE GOOD GUY TO WIN
Me: 46 H:44 Together: 25 years Married: 20 years Separated: 11-30-06 Divorced 12-21-07 OW: EA began 2005 PA began end of 2006 3 children,20, 16, 6 ex asked for forgiveness 01/16/11