I do work from home and am father of two small kids (3 and 1 years), both kids and my wife are stayign at home.
From the begining we set strict rules: my office is off place: nobody except of me can go inside, kids are taught that when I am inside I am not home and they just can't see me. I am also not going inside my office outside of my business hours.
With those rules in place it feels like having office outside with minimal commute.