Here is my 2 cents: I think the mom that has access to the whole week needs to pay for the whole week. That is only fair. I also think the family that needs Mondays should have to simply wait until there is a Monday available and that is just the way it goes. They pulled out. They could have paid you to hold their space so you would have it when they returned. I am assuming they didn't or you wouldn't be in this boat in the first place right?
Also, I completely understand that you feel obligated to this family since they provided work for your husband, but.....did they do it because they expected special treatment or to get something in return? If they did, that was NOT fair to you, your business and just generally not nice at all. If they did it because they needed an employee/worker, then they got exactly what they needed and it shouldn't really have anything to do with daycare as that is a completely separate issue.
If you really want to take the child back, I would honestly see if you can get a variance for Mondays. If you don't want to go over your capacity limits and make accommodations for this family, you are just going to have to be honest and tell them you don't have room. Making the new family give up something you gave them because someone else wants it is just not good business practice and really not their problem...kwim?
I would make new family start paying for full time space access though.....
I am NOT trying to be harsh, just real.
