@welcome2atlantis depends on how poor we are talking, selling flowers is a fairly lucrative business in a first world country because you can guilt saps into paying for overpriced dead plants where they cant say no otherwise they look like assholes.
now, where prostitution is illegal, a flower or something else equally 'worthless' or of low value will be sold at a relatively high price., if it sounds to expensive and you are in a bad area where saps cant be milked, that's likely prostitution done in a way that cant be directly proven that's what it is but everyone knows.
if a kid is doing it, and this isn't a pitch black world, its almost always just a way for the kid to earn money to help out.