Seattle Jellies: Can you point me to a website preferably local to you that tells where one can find temporary rentals for a friend and her family for three weeks in Seattle in July this year?

I know it’s short notice, but I figure the U district must have some listings because of the transient nature of students. The course is on Westlake and Denny, but I’m pretty sure they’ll have a car. Any info is appreciated! Thanks.