It seems like for everything you've been through with her, your reaction and feelings are probably normal.
As the others have already said, you're still in the middle of the thing, still processing, more healing on the horizon. The way you feel and do things will change in time.
In your shoes, I'd probably feel especially uneasy when the kids were with me. It's one thing for you to put on a poker face and deal with her in passing, it's something else entirely for the kids to be subjected to a surprise interaction. Maybe sticking close to home for mental safety sake isn't such a bad thing? As long as you and the kids still find ways to socialize and have fun.