I am not a professional and I really feel like that's whose opinions you need the most right now but I will weigh in briefly.
I think that now is NOT the time for your wife to be alone let alone responsible for the children. There should be NO talk of OM or R or M or anything but getting her to a therapist consistently, becomes clean and sober and the health and care of the children. Those are the ONLY priorities. Her wanting the OM, her believing you're trying to take the children... none of that is an issue right now. I'd be careful to make your moves very obvious that you're NOT trying to disappear with the children because an accusation in that department could make your terrible situation worse.
Was there a social worker at the hospital? There should have been an inquiry about the children and whose care they are in. They are too young to be facing this.
Your wife wants to be home with the kids but I wouldn't want my kids around her until she is clean, sober and mentally stable. That is just not the case right now.
Attending a wedding after your wife's suicide attempt? I'm so confused by that.
