Obviously I cannot speak to the story in the tweet actually happening, but I’m not so certain that this couldn’t happen for two reasons:

1. People who spend money on a cute, innocent kid’s lemonade stand are probably not stingy. After all, you’re never really getting your money’s worth there and it’s more about the (arguably) good deed.
2. Once the kid (re)acts in a way that makes it seem it is convinced the money is its, it’ll feel like stealing from a kid to ask for the change back.