Absolutely, this is DBing. Keeping it civil and calm with her when you do speak regarding the kids. I would not tell her again that she has what she wanted, ie, filing for D, the house, etc, because all you will hear is her telling you again how hurt she is by the past, and so on. I wouldn't even mention it.
At this time, do not even get into any conversation that has anything to do with you two, only those that involve the care of your children. If she persists in asking you about your feelings or starts talking about your M, then find a way to end the call politely, like you have another call or have to be somewhere or something. You know, nice and detached.
She is not ready for the "end it with om" ultimatum. I would not go this route, until she says she may want to work on your M. I don't think it will go well at all if you do this.
Be patient, it may be awhile. The best thing you can do is what you are doing, staying off the roller coaster, and enjoying your life, and enjoying your kids.
