If you are married and have decided to file as married filing separately, then you can't use an FSA for day care unless you also claim the child as a dependent.
If you are unmarried and living together, you can't use an FSA to pay for day care unless you also claim the child as a dependent.
If you are living apart and sharing custody under a court order (never married, married but separated, divorced) then you can use an FSA if the child lives with you more than half the year. In that circumstance, the parent whee the child lives more than half the year has the automatic right to claim the child as a dependent. They can release the dependent exemption and the child tax credit to the non-custodial parent, but the right to claim the child care expenses always stays with the custodial parent.
If you are living apart and sharing custody under a court order and the child lives with you less than half the nights of the year, you can't use an FSA under any circumstance, even if the custodial parents gives you a release form to claim the child as a dependent.
