Thanks for the update. What, exactly, are you having second thoughts about? Enforcing your boundary?
Not only would I LET her move out, I would have replied "Well, you need to be out by ______," and give her a week. On the seventh day, while she was gone (preferably wait for a time you know she is with OM), pack up all her stuff and leave it for her in the front hall by the door, and offer to drive her anywhere she wishes.
Dan, you've manned up and gone from allowing her to wantonly cake-eat right in front of you and your sons, to standing up for yourself, your family, and learning to set and enforce boundaries. Back down now, and you'll regret it for the rest of your life.
