Does your church offer any kind of counseling? That would be my first go-to if it does. I don't think AA has to come before or after the marriage. I think it can coincide. Your wife being so close with a member of the opposite sex is her playing with fire. I think, in a marriage, one needs to ask themselves "would I say/do this if my partner was right beside me?" If the answer is "no", then you've crossed a line. Emotional affairs are very real and can be every bit as destructive as physical affairs.
It sounds like she's cooled off of this person, and that is good. I think being in an all women's group is good as well, because there she can feel free to discuss things openly whereas in a mixed group there might be reason to hold back in some areas.
Unfortunately, my husband has never really gotten into any long-term recovery program. From what I've read, though, the dynamics can change in a marriage during recovery, offering challenges of their own. Going to Al-Anon could help you with that, and if you're religious, I think prayer can help with that, too.