You can control her BL. Shes a selfish idiot right now (maybe always was). You need to realize she wont be following your expectations or any agreements. If you read other threads you'll see this behavior is common for WW. What did you reply to S5 in the car?
IMO it is totally OK (and frankly I suggest) for you to calm down your kids and tell them mommy is doing fine. Tell them you dont know exactly what she is doing but assure them she is ok. Make sure to explain to them it is in no way their fault.
Me: 34 Stbxw: 30 D:5 D:3 Mini bd: May/June 2019 Married: Aug 2019 BD: 6th Dec 2019 OM Confirmed: Feb 2020 March 2020: I filed for D Waiting for D to be finalized and W to move out end of January 2021