Have you tried scolding your family members when they are smelling the room? If so, did it make a difference? There are a lot of things the peeps do that don't have any real significance in the game, and different players are going to view them differently.
Would I scold them for smelling something funny in the fridge, or smelling smoke from the stove? It would never have occurred to me to scold them for smelling something wrong in their home because they live there and can sniff out odors that I cannot. Popping a pimple, on the other hand, is immediately reprimanded!
We gamers learn to go with the flow because game puzzles so often rely on the game developer's logic. You know, how in an adventure game, a glass cutter must be used to enter through the window of an abandoned shed when to our minds, that rock we have in our inventories should work as well! };-)