Kids get a lot of heat for asking authors how much money they make. Believe me, adults want to know, too. They just aren't as honest about it. They'll say things like, "Do well with that, do you?" when they hear you're a writer to try to get a feel for how much cash you're taking in. (The correct answer to that question, of course, is a simple no.) Or they might ask, "Does that pay well?" or "How does that pay?" so that they can pretend they aren't asking how much you, personally, make. But they are.
I would much rather have a kid ask me how much money I make than how old I am. Once a kid did ask me that. I laughed it off and said I didn't answer that question. Someone raised her hand and said, "Tell us when you were born, and we'll work it out ourselves." (The correct response to that is, "Children your age can't work with figures that large.")
Thanks to Camille at Book Moot for the Slush Pile link.