Thanks CW!
We wont need an actual agreement and I am sure thing will unfold as we go.
My main concern is that the kids feel comfortable but I have also learned that XW tends to assume things and typically we dont have the same idea.
I will probably suggest we share costs for outerwear, shoes, equipment etc. Clothes will be mostly paid for by oneself.

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