From the article on monster homes Big Bigger Biggest I found this snippet interesting..
<snip>The Banner children, Erica and Danielle, have their own bedrooms and private baths. Mrs. Banner has noticed, though, that the girls usually sleep together in Erica's double bed<snip>
BIg house but the children feel isolated so they abandon one room to keep each other company, much like the Smart sisters did(Elizabeth Smart was abducted from her parents sprawling 6000+ sq ft. home in Utah a few weeks ago. She and her younger sister were sleeping together in the same room)