A known lover of music and song, Jocelyn is often seen in the company of her elder sister, Margaery, leading to the rumour that she and the eldest Roxton daughter are in an illicit relationship.
She is twenty in 514 AC.
Jocelyn travels from the Ring to Oldtown with her family to attend a Ball held by Lady Ashara Lannister. During the journey, she and her sister Margaery witness signs of their sister, Alicent's madness.
Whilst at the ball, Jocelyn dances with and befriends Elyana Tyrell, nicknaming her 'Little Rose'. She then looked after her whilst Melessa Tyrell gave birth. Whilst returning to the Ring from Oldtown, she witnessed Alicent attack Margaery in a fit of paranoia.
After being invited to serve as Melessa Tyrell's handmaiden alongside her sister, she and her father and sister, Margaery, travel to Highgarden. Whilst on the journey, she stopped at an inn, 'The Blue Orphan'. Margaery voiced her hesitation about taking up the position, at which point, Jocelyn convinced her to try. After which, she kissed her, hinting at her deeper feelings towards her elder sister.
After arriving at Highgarden, and while her sister still hesitated in her decison, Jocelyn was quick to accept, soon settling into her role as a handmaiden. She slowly stopped trying to persuade her sister to accept Melessa's offer, albeit not completely. She busied herself with her duties, once more earning the friendship and affection of Elyana. As the relationship between Margaery and Melessa soured, Jocelyn found herself entirely unequipped to deal with her sister's ever growing stress and confusion.
When a contingent of Dornish to came to Highgarden to discuss a trade deal, she did her best to keep Margaery out of trouble, and also met Ashara Dayne with her father. During the course of the first night of the visit the relationship between the Roxton sisters changed dramatically, much to Jocelyn's own happiness..