Wash. Rev. Code § 26.16.205
The expenses of the family and the education of the children, including stepchildren, are chargeable upon the property of both spouses or both domestic partners, or either of them, and they may be sued jointly or separately. When a petition for dissolution of marriage or state registered domestic partnership or a petition for legal separation is filed, the court may, upon motion of the stepparent, terminate the obligation to support the stepchildren. The obligation to support stepchildren shall cease upon the entry of a decree of dissolution, decree of legal separation, or death.
RCW 26.16.205
Part headings not law-Severability-2008 c 6: See RCW 26.60.900 and 26.60.901.
Effective dates-Severability-1990 1st ex.s. c 2: See notes following RCW 26.09.100.