Mo. Rev. Stat. § 452.220: Married person entitled to proceeds of earnings of his or her minor children, when.

Such married person, during the period his or her spouse shall fail to provide for his or her support, as stated in section 452.130, shall be entitled to the proceeds of the earnings of his or her minor children; and the same shall be under his or her sole control and shall not be liable in any manner for the spouse's debts.