(a) The parent or guardian of a child is liable to the state or to the county for a payment made by the state or county for foster care of a child under this subchapter.
(b) The cost of foster care for a child, including medical care, is a legal obligation of the child's parents, and the estate of a parent of the child is liable to the department for payment of the costs.
(c) The funds collected by the state under this section shall be used by the department for child welfare services.