It's rough isn't it? I mean it's so clear that this A fits right in with all the other methods of escape you listed, but she won't see it. Maybe she does, but she doesn't feel she can do with out. This is where detachment is critical. You NEED to allow her to make mistakes she chooses to make. If you can accept that she is her own person with her own choices to make (yes, they impact you and your child), but they don't reflect on you, you will put the full burden of personal responsibility back on her shoulders. As long as you shoulder that burden for her, she's obsolved of it to a degree, she doesn't have to worry as much, because you've got it covered.
I think she needs to grow. She needs to mature, and this may take time, trial and error, etc. Hang in there, keep living your life and try and observe and acknowledge all the positive there is in her. Pain is a fact of life. It's always going to be present. She can choose to work through the pain and get to a place where she's done what she could to live up to her expectations for a wife. If she doesn't do this, she's going to always have that baggage to carry around with her, she'll constantly have something to escape. She needs to come to this on her own, and while you remain distant, working on bettering your life (of course with positive implications on her life, should she choose to continue it with you) she will have lots of time to think. It's important to remember that these affairs are not just about lust or love or similar feelings, but are results of deeper feelings and need to be happy. It's a misguided, temporary attempt at achieving this, it's better than where they were, in their heads, but it's not the solution. They are taking a big risk and hoping that it is the solution they've found. They work hard to make it so, but it can never be. They need to find this out for themselves, but in the mean time, you can work on finding the REAL answer to this question, and hopefully, once the recognition is there that the A isn't the answer, you'll be in a position to explore a better option with them.
“No problem can be solved from the same level of consciousness that created it. ” – Albert Einstein
