I don't know what to advise, but she should not get away with talking to little D about OM and telling her that Mommy likes OM, etc. That is so unacceptable! Then....so is an A.

This woman will only continue to get worse, IMHO, and until "she" began to suffer from the from her own bad choices, then she is not going to slow down. I don't know of anything she has had to suffer personally! It has been her family that has been put through the ordeal of her unfaithfulness to the M.....not her! And now for a "mother" to be teaching her little girl the crap she is telling her.....and there's no telling what else she has been saying trying to get the D's approval about OM. If you can think of something to hold her feet to the fire where the child is concerned, I sure thinks she needs to be accountable for that terrible behavior of bad parenting.

It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!