2) I want to give the R with OM ample time to burn out if it can/will. If she's bringing him around the children, it will be a sign of a much greater commitment. Yes, this is manipulative. But she hasn't been unmarried for more than 1 year and 1 month since she was 21. I want a chance, I'll be honest.
From my own direct experience, it doesn't always signify commitment per se. My mother was a former WAW who married the OM. Guess what happened? Their marriage lasted less than two years. Go figure.
Let your W and OM experience dealing with the mundane stuff such as wiping snot, dealing with a screaming child, etc, etc. Their bloom is bound to wear out faster this way instead of the illicit affair grabbing quick meetings here and there.