You can't. The child care credit requires that both spouses have "earned income." (That is, income subject to social security or self-employment tax.) Forms of income that are not earned do not qualify you for the credit. Since the IRS has determined that certain caregiver income is not taxable earned income, it can't be used to qualify for tax items that require earned income (such as the child care credit, certain IRA contributions, and a few other things.)
If being a non-taxable caregiver was going to allow you to claim the child care credit, that would have to be changed by Congress.
