Amy.....he is a grown adult....and so is she, for that matter. They are fully able and have the free will to choose their own actions and make any choices that they want.
We humans have natural cu riosity and interest, I think....but, beyond that---obsessing over them in a micro way is giving them too much of your own head space. They sure as hell are n ot lying awake , at night, worrying if you are happy, or crying or improving with age...lol.
This, as I see it, is about you placing your own internal boundaries to protect yourself. Without these kinds of mental boundaries.....it will make you feel sick...it will make you feel "out of control" and make you feel "crazy".
Rather than think about him having a happy life....redirect that mental energy to thinking about what you can do to let Amy have a happy life.
The 3 Cs......you didn't Cause their problems; you can't Control their problems; and you sure as hell can't Cure their problems......
The same applies to your ex=husband's abuse of you. You didn't cause it...you couldn't control it (only control yourself, ultimately)....and you couldn't cure it (not even now).
dandylion