Ah, the difference money makes!
I've been smiling at several posts here from people emphasizing that Gigi was NOT being trained to be a hooker, but a COURTESAN! Ah, the difference money makes! What is a courtesan but a high-class hooker? Not to say there weren't major practical differences between a streetwalker and a courtesan, but the point was that a courtesan was a woman being paid (mainly) for sex by a man who could not or would not marry her. Of course, a man of discrimination would also want a woman who was good company, attractive, knew how to live well and how to behave in public, but without the sex the rest of it was pointless.
On the other hand, I know that long-term mistresses of the era had a kind of semi-respectable status that prostitutes lower on the social scale certainly did not. I hadn't realized before that legal documents were actually signed, stipulating exactly what the gentleman was going to provide for his mistress.
"Gigi", like "Pretty Woman", is a frothy, pretty, extremely well-done film (with gorgeous clothes) about a basically depressing subject.