vocabulary bombs

"Mommy, can we play bomb cellar?" Naiya just asked me.
I'm a little taken aback by this question.  Where on earth did she hear about bomb cellars?  I fear someone has been telling her frightening stories.  Maybe, as is often the case, she just overheard someone talking and so is trying out some new vocabulary.
"How do we play that?" I ask, worried about where this is going.
She looks at me a if I'm a bit dim witted.  "I'll go get the balm," she replies, "and you be the seller." 
"Oh," I dumbly respond as she runs in the next room for her lip balm collection.