AFWAW, Steady...stay Steady...PDT is right - you are starting to pursue or be wimpy. This is not a sprint but the beginning of a marathon that will last for years...I am sorry to tell you this but feel it best you know and accept upfront that you are on a hard road that will change you and yours forever. It is up to you to make sure that change is for the better...and you may get back together for several years and YOU may decide you don't want her at all.
Your fear of exposure is understood. Although, exposure will not cause your divorce...you doing nothing and letting the affair to continue will though. Guaranteed people in her shop know, I would not be surprised if her 1Sgt has not heard anything. Your goal is to expose to prevent the affair continuing as a fantasy with no real world responsibilities. Exposure will do that in a hurry...if you are worried have your shirt talk to her shirt offline to investigate. What would it hurt...you are already living apart...she might be mad for a few days but will have to accept it was her actions that caused this.
Your wife could also want your daughter to aid in her attempt to get CS from you (or not have to pay you anything). Believe nothing she tells you for now...she has already proven to you that she cannot be trusted. You do nto want her to have custody every weekend...you will never have quality time to do something with her
I know how easy it is to get excited and if you keep doing this every time she yanks your chain you are going to be a nervous wreck or worse get angry and say/do something you will regret. Always keep in your thoughts that you want your daughter to be proud of you...that will keep your moral compass true.
It is possible the affair is over...with her having possibly four affairs while you were gone who knows whom she is talking to and hoping for some fantasy relationship...I say that because she could think that #2 was her soul mate or some other silly thought right now and is hoping to reestablish something with him or #1 or #3 (assumming that #4 was the Lt Col and that is over because he is married and PCSing in Oct)
Enough rambling...take care of your daughter (#1), yourself and enjoy life...might as well smile because crying is not working. Godo time to think about church...if for no other reason than it exposes your daughter to a different lifestyle and will give her a good moral base to make her decisions later in her life.
PS. 205 is not that fat but 175 is better. Take care.