Take a deep breath and let it out. She wants you to loose your cool and you can't afford to do that. I agree that she should have called you. When you see her let her know that it should be a courtesy to communicate about the kids no matter what is going on between you two.
It S**KS that she is trying to put the kids in the middle, they do not deserve to be disrespected like that. They are kids and should be allowed to have stable childhoods without crappy trauma like this. Even though the kids are not yours biologically, you still have strong ties to each other. Stick up for kids since they can't do it themselves.
As far as her new frillies. Sometimes you need an ego boost and a reminder that you are still feminine. Especially when there is a hollow blackness inside. Could also be that she just wanted some new things. You can have an A wearing burlap. I would be watchful but not drive myself crazy with it right now.
She is yanking your chain, trying to get you to lose it. You cannot allow that to happen at all. You will give her all of the power if you lose it. Come here for strength and advice. Even if she is treating others like cr*p, don't fall for that trap. Don't be a doormat, either. Patience is power. Breathe, deep and slow.