Jill hails from the Talrega region of Daein, and is the daughter of the famed Wyvern Lord, general Shiharam. Jill aspires to be a renowned Wyvern Lord like her father, and first appears as a novice-ranked Wyvern Rider.

During the Mad King’s war, after the Greil Mercenaries are rescued by Goldoan soldiers and Prince Kurthnaga, Jill defects from the Daein army when she spots Ike's forces battling pirate Ravens and joins the liberation effort for Crimea. She later reveals that her main purpose for joining the battle was to experience the thrill of hunting Laguz. As Ike's army continues traveling into the domains of Begnion, Ike questions Jill's purpose in staying with his army, despite having the right to leave. She replies by revealing that she has been raised to believe that laguz are evil. If Jill is deployed to participate in Chapter 20, she will be able to face off against Shiharam on the battlefield. If she lacks an A support with Mist at this point in the game, Jill will defect to the Daein army upon conversing with her father.