No good deed goes unpunished.

Unfortunately, she was your tenant, in spite of no lease or written agreement and the WA landlord tenant statute covers tenants' abandoned property in RCW 59.18.310.

http://apps.leg.wa.gov/RCW/default.aspx?cite=59.18.310

Never mind the rent part, just read what you have to do about the abandoned property, especially the part about written notice. You'll need to follow the procedure to the letter otherwise you risk getting sued for the value of the property.

Since you need to clear her stuff out in order to repair and sell your home, self-preservation gives you no choice but to rent a self storage place and move all her stuff. Once you get her stuff out you'll be able to concentrate on locating her for proper written notice. I know, you'll have to spend money to store her stuff. That's too bad, but it's your tuition for a life lesson from the school of hard knocks.