I think this was a novella or long(ish) short story, maybe in an anthology - I read it in England but it was set in the USA.
What I remember:- The people in a town are going about their business but you realise by their conversations that they're being mind controlled by this young girl - possibly aged six. (It made me think of The Mule in Foundation or Bill Mumy in the Twilight Zone "it's been a good day")
One couple are chatting to a friend in the street, they casually mention that they're selling their house because they need enough money to get 24000 peanut butter and jelly sandwiches, the girl has told them that's what she wants soonest.
Another person, I vaguely recall him being the doctor, is trying valiantly to entice businessmen to the area to raise cash, she wants a theme park in front of her house.... I think once they arrive they come under her control, even if they then go thousands of miles away to attract capital.
There was also something about making the local kids live like monkeys, but their controlled parents didn't mind.