Wash. Rev. Code § 26.33.420
The legislature finds that the importance of children's relationships with their siblings is well recognized in law and science. The bonds between siblings are often irreplaceable, leading some experts to believe that sibling relationships can be longer lasting and more influential than any other over a person's lifetime. For children who have been removed from home due to abuse or neglect, these bonds are often much stronger because siblings have learned early the importance of depending on one another and cooperating in order to cope with their common problems. The legislature further finds that when children are in the foster care system they typically have some degree of contact or visitation with their siblings even when they are not living together. The legislature finds, however, that when one or more of the siblings is adopted from foster care, these relationships may be severed completely if an open adoption agreement fails to attend to the needs of the siblings for continuing postadoption contact. The legislature intends to promote a greater focus, in permanency planning and adoption proceedings, on the interests of siblings separated by adoptive placements and to encourage the inclusion in adoption agreements of provisions to support ongoing postadoption contact between siblings.
RCW 26.33.420