I thought nesting was leaving the children in the M home, while mom and dad took turns being with the children, while one of the parents stayed in a temporary place.

Exactly how would you benefit from this nesting arrangment? You already have a place to live when you are not with the children. Is she suggesting you rent an apartment for her to stay while you are in her house with her parents.....visiting her children? Wouldn't it be cheaper to go to her state, get a hotel room, and get the kids when it's your time.......rather than paying rent full time?

It sounds fishy, to me. Who suggested the nesting arrangement?

It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!