AFWAW, Kalni brings up many valid points...not that I agree. I do think the only chance your marriage has at this point is to expose. You are correct in your thooughts that she will probably not get "punished" meaning she will not lose a stripe and will probably just get marked down on her EPR and no decoration. That will guarantee she will not be promoted...now if she is given a no contact order and she violates that then all bets are off on what her CC will do then. Most do not like to be disobeyed when issuing a written order...the implications are to broad for lack of detail in other areas to ignore.
Exposure will not end your marriage...the affair might but not the exposure...what the heck, if they are really in love then why not let everyone know...stay focused and do what you have to do...this is not the time to overthink every decision that you make...end the affair, take a break, then get on with working on your marriage.