And go in with zero expectations, don't assume she's ready to reconcile or anything else that will lead you to disappointment. Just assume she wants to work out logistics and be prepared with your plan.
Now if she does blindside you with a desire to rebuild the M, just tell her that's not what you expected to discuss and that you need some time to gather your thoughts and make a future date to talk about it. DO NOT get all googly eyed on her! Keep your game face on! Tell her in the meantime you want expanded custody of your S.
