Yes it's your choice. But is it your choice to get sick from the lemonade if some foul ingredient was in it?
It's a matter of possibility. Kids usually aren't that renowned for being the most sanitary bunch of humans. And they aren't taking away from their time to hunt down kids trying to sell lemonade to pedestrians, she simply drove by and saw it.
I don't care if it's a possibility. If people die from getting sick from some lemonade, then the Law will deal with that matter. But to completely forbid industriousness is completely insane! Isn't that US government hostile enough to business that they need to start going after lemonade stands? Are we so coddled, cowardly, and weak that we actually want the government to?
Law Enforcement already go after raw milk producers, denying people their right to choose wholesome milk instead of the trash the USDA allows to be put out. They go after private food cooperatives for selling truly organic food.
This is tyranny and rule through fear. Plain and simple.