Washington Revised Code Title 11. Probate and Trust Law § 11.125.410. Agent authority--Principal’s minor children

(1) A parent or guardian, through a power of attorney, may authorize an agent to make health care decisions on behalf of one or more of his or her children, or children for whom he or she is the legal guardian, who are under the age of majority as defined in RCW 26.28.015, to be effective if the child has no other parent or legal representative readily available and authorized to give such consent.

(2) A principal may further nominate a guardian or guardians of the person, or of the estate or both, of a minor child, whether born at the time of making the durable power of attorney or afterwards, to continue during the disability of the principal, during the minority of the child or for any less time by including such a provision in his or her power of attorney.

(3) The authority of any guardian of the person of any minor child shall supersede the authority of a designated agent to make health care decisions for the minor only after such designated guardian has been appointed by the court.

(4) In the event a conflict between the provisions of a will nominating a testamentary guardian under chapter 11.130 RCW and the nomination of a guardian under the authority of this statute, the most recent designation shall control.