Not an expert, but YES, they could have an EA and not realize it, because that's what happened w/ my WAH. A couple weeks after BD (before I was DBing!) I pushed him hard on "Why would you just leave without talking about it? There must be someone else?" He said he wasn't having an affair and I kept pushing... "Maybe there's someone that you've been talking with that you share things w/ that you used to share with me?" THEN it came out "well, there's this woman at work I've been talking to. She's really nice, she's cute, she listens to me and I listen to her, we have things in common to talk about, blah blah blah". When I described an emotional affair he said "Well, I guess that could be what it is..." In my reading, a key aspect that moves it from friend to EA is the secretive nature. If she was truly just a friend I would have heard about her before. He also knows there is not likely a future with this person (she's married, has kids, pregnant actually right now, has made no indication to H that H is anything more than friend much less considering leaving her own H!) but still maintains communication with her. It could also be a one-sided EA which makes it harder to recognize. I don't have much advice for you beyond letting it go.. you can't control her interactions with him. Their "friendship" is out in the open, so to speak, so perhaps losing the secretive-ness will help. It may be obvious to you there's no future with this guy, but maybe not to her. She has to see it on her own. I would liken it to a teenager who wants to date the "bad boy" even MORE when her parents try to prevent her from doing so, even if she may know it's not the best idea. You just want to do it even more when someone tells you you can't. So, don't be the one telling her she can't and maybe the excitement/intrigue will die out!
Me:30 H:29, no kids T:12, M:4 (when D was final) 12/13: "Don't think I want to be M anymore" 6/14: Separated (I move) 1/15: H filed for D 5/15: D final