Thanks, Kelly!
I kind of thought as much, but haven't paid much attention to the extensions in the past. I "stole" the Modern House at Craigslist for $45, fully furnished with only a few small pieces missing (oh, and minus a bathroom!), and I really want to expand it to make room for the nursery and a bathroom! (It came with kitchen, living, office, master bedroom, and kids' rooms!) I think I'll just break down and buy the extensions before they're gone and I end up having to kick myself!