The amount of a kinship guardianship subsidy shall be determined according to this section and as provided by rules of the department. The subsidy may be paid monthly and the monthly amount may not exceed the monthly foster care maintenance board payment for the child if the child were to remain in the care or custody of the department, without regard to the sources of the funds. No foster care maintenance board payment and kinship subsidy payment shall be paid for the same child for the same period of time. The kinship guardianship subsidy may only be provided for an eligible child. Subject to rules adopted by the department, the subsidy may include up to the federally established amount for nonrecurring expenses, including attorney’s fees, incurred by the kinship guardian or successor guardian to complete the kinship guardianship or successor guardianship in court. Subsidy payments are subject to the availability of funds and the allocation of funding by the department.