The personal earnings of the debtor are not exempt from an order, judgment, or decree for the support, as defined in section 252D.16 , of a child, nor from an installment of an order, judgment, or decree for the support of a child. [C24, 27, 31, 35, 39, § 11765; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §627.12 ] 85 Acts, ch 178, §13 ; 97 Acts, ch 175, §239 Referred to in §512B.18 , 642.21