House

Definition: a. A structure serving as a dwelling for one or more persons, especially for a family.

 I think a couch makes a great house.  Each of those pillows she said were her rooms.

b. Something, such as a burrow or shell, that serves as a shelter or habitation for a wild animal. 

The laundry bag definitely makes a great shell for a wild animal!

Gotta love the imagination of a three year old.