Ylenna was the bastard child of a woman by the name of Elaine who lived in Korvosa. She never knew her father, but she has noticed that she has peculiar abilities, and suspects that her father must have had some sort of either infernal or elemental blood in him.
When Ylenna was eight years old, her mother married a man named Harforth, a local fisherman. Two years later, they gave birth to Ylenna's half-brother, a boy they named Roland. When Roland was six and Yelnna was fourteen, both of her parents were killed, lost at sea when they were out on a fishing vessel. Since then, Ylenna has done her best to eke out a living either doing odd jobs or trading on her strange arcane abilities. While not everything she's done has been strictly legal, she hasn't had to stoop to anything too terrible, and she's not had trouble with the law. Meanwhile, she did her best as a teenager to raise Roland
Several months ago, however, the fourteen-year-old Roland went missing. Ylenna and Roland had been fighting; Roland was going into his teen years, and despite the fact that she'd been raising him, and despite the fact that she was finally at an age where she might normally have thought of starting a family herself, she wasn't entirely prepared to deal with a rebellious teenager. The first few days he was gone, Ylenna didn't worry. Having grown up as a child who had to act older than her age, she had taught Roland how to cope on the streets. However, after that she began to get worried, afraid that he had either fallen in with the wrong sort of people, or that he'd been out-and-out kidnapped. She started trying to find Roland. Alas, she could not get the authorities interested, and she's become increasingly desparate. Recently, she's come to strongly suspect that Roland has been kidnapped and force to work with Gaedren's gang, but she has yet to come accross hard proof of that.