Mademoiselle Rose-Annette Bron (Rosanette)
First things first. Courtesan is basically a fancy word for a fancy prostitute. There's more to it than that, and the history of courtesans is long and complicated, but all your need to know about Rosanette is that she's mistress to a bunch of different men: Monsieur Arnoux, Monsieur Oudry, Delmar, and of course, Frederick.
If we had to describe Rosanette in three words, we'd probably go with the following:
- wild: "On Sundays they played charades; Rosanette, more noisy than the rest, made herself conspicuous by funny tricks, such as running on all-fours or muffling her head in a cotton cap" (1.8.195).
- emotional: "After spasms of gaiety came childish outbursts of rage, or else she sat on the ground dreaming before the fire with her head down and her hands clasping her knees, more inert than a torpid adder" (1.8.195).
- open: "Without minding it, she made her toilet in his presence, drew on her silk stockings, then washed her face with great splashes of water, throwing back her figure as if she were a shivering naiad; and her laughing white teeth, her sparkling eyes, her beauty, her gaiety, dazzled Frederick, and made his nerves tingle under the lash of desire." (1.8.195). P.S. "making your toilet" means putting on make-up and getting dressed. Probably shouldn't throw that one around these days.
Sounds like a fun companion, but it's clear that Frederick is mostly with her because he can't be with Madame Arnoux. And why not pass the time in the party lifestyle? But after some initial (mostly sexual) excitement about the lady, Frederick realizes that she's kind of boring and kind of tacky—she thinks Fontainebleau is a yawn, and he's apparently not a fan of Turkish parlors complete with a hookah.
Oh, but that doesn't stop them from having a baby together. The baby dies as an infant and Frederick leaves Rosanette. So suffice it to say, things don't end on rainbows and butterflies for this poor working-class girl.