I don't think she's consciously trying to be disrespectful, I think she's just angry and crazed about the situation and lashing out from an emotional reaction. The best way to deal with a crazy person is distance and detachment. I wouldn't take it personally.

Yes, the jerky behavior makes it easier to actually want the D and go through with it. A momentum gets started.... If you in any way want to keep your family together (and no matter what crap she's throwing at you right now, in the long run it would probably be best if you did... because D never really fixes anything and has it's own set of problems...), the best thing to do now is distance from her. If she acts like a bitch (and do expect her to, she's going through a crazy time) just calmly tell her you refuse to talk with her until she calms down and hang up or leave.

You both need to distance and try to calm down. If if you keep up this fighting you will destroy your kids.

There is no arriving, ever. It is all a continual becoming.