How about a cat bowl bed? Ravelry has lots of cat bed patterns. http://www.ravelry.com/patterns/sear...ptioned_thumbs
BTW I wouldn't want a ferret around my home. Why people love them baffles me but to each their own, live and let live, etc., etc. My downstairs neighbor keeps a ferret and basically it's the ferret's apartment that it shares with her. I hope your peace offering does the trick. It's so easy to offend someone, especially a child, without even meaning anything really negative.