Legal Question in Family Law in Washington

You ask something I've never dealt with before, so this is a stab in the dark answer, and hopefully, another attorney will see it and chime in here with additional information if they have faced this situation. Most folks in your position do nothing. They just leave the kids with family and head off on vacation.

If you want your sister and her husband to make medical decisions, I suppose you could always call the local hospital and ask what you would need to have on file for purposes of acting as temporary guardians of your children. They may have such a form on file. Usually though, if someone brings in a family member, such as an aunt bringing in her niece and the mother is out of town, the ER will treat the child to stabilize them, and then depending on the hospital's policies, either allow the aunt to make decisions for the child, or if the child is stable, try to contact the mother to see what can or should be done.

I suppose you could also hire an attorney to draft a document for you that you can sign and which is notarized detailing your wishes, but whether a third party accepts such a note is entirely up to the third party. Beyond that, as far as I know, there is no legal process whereby you can go into court and ask the Court to enter orders to assign your sister and brother in law temporary guardianship for a week. I may be wrong on that, but I've just never seen it.

I am sorry I cannot be of more service to you, but as I said above, I have just never faced this situation and so I am taking a stab in the dark on this one. Please let me know how you eventually resolve your situation.