There is an article in the Healing Library about modified NC for D with kids.
You basically set up very firm boundaries about communication how, when, what, etc.
I recommend that you communication only via email or test. That will provide documentation if you ever need it and prevent you from being pulled into "friendly chit-chat". It allows YOU to decide when to respond and what to respond to. And you only want to respond to questions about kids or finances. Ignore everything else.
Some of the folks here use goggle calendar or my family planner (? I think that is what it is called) to coordinate kids schedules and activities.
Best of luck.