Johanna is not just any courtesan. She comes from House Swann, a Noble House of the Stormlands. Johanne is known as the Black Swan and is extremely influential in the Free City of Lys.
Ch 35 Chapter 35: A Message from the Lovely - 116 AC
I getting more curious what dragons Aemon and Gaemon will bond with. I'm guessing Vermithor for Aemon and maybe Silverwing for Gaemon, was he wanted a smaller dragon or maybe Sheepstealer.
Ch 31 Chapter 31: Of Tourneys and Tournaments - 112 AC