I know here in PA, if the child is going to a private school (which a preschool would be along with not being mandated by the state) then either the parents have to agree or it needs to be paid for by the parent who chooses it as in the case of one of my friends. Custodial mother wanted him in a preschool and catholic school later. Both were shot down by domestics as something that the father had to pay for because it was not a nec expense. Daycare may be, preschool is not. School (starting at 1st grade here) is private school is not. I would look into things and see if the same is true where you are.