Jenny, also known as Penny Jenny or Redgrass Jenny, was a whore during the reign of King Daeron II Targaryen.
She was a camp follower of the forces of House Blackfyre prior to the Battle of the Redgrass Field. She supposedly lay with dozens of men, possibly including Ser Quentyn Ball. This was where the nickname Redgrass Jenny came from.
Afterwards, she returned to King's Landing and began working at an establishment known as Pussywillows. Here she birthed a son and a daughter, who she claimed were sired by Ser Quentyn. After her death the whores would continue to raise the two children.