DO NOT fight with her, esp. in front of the kids. This is VERY important. DO NOT! I am not saying you have to bow down to everything she says/does, in fact I am saying you do not grovel.
Leave the room, do not get pulled into heated arguments. You tell her once (calmly) that you will not be talked to in such manner and if she continues to bait you, you will leave the room. Then if she starts, just calmly leave the room. Not in anger, not in haste, just calmly leave the room, if she continues to follow you, just go out for a short stroll.
Let go of the need "to be right". It does not matter, you see that she is baiting you all the time to get a reaction out of you, most likely to pave the way for divorce proceedings. Be the bigger person and DO NOT GET DRAWN IN.
