Rose Sheedy is a 17-year-old female student who attended a private school on Roosevelt Island via an academic scholarship, coming from a financially strained background. She cared for two younger siblings during her mother's hospitalization, following her father's abandonment shortly before her mother's illness, leaving Rose as the primary caretaker. A friend named Sarah later located her father, leading to his return and reintegration into the family. This provided Rose relief that her siblings and mother would have support after her eventual disappearance.

Initially extremely shy and reluctant to fight, Rose's cowardice in combat placed friends in peril. A pivotal moment occurred when Rachel nearly died due to Rose's inaction, prompting Rose's resolve to confront threats despite her fears. This transformation culminated in her realization that she must live fully without excessive worry about the future, accepting her responsibilities. By episode 18, she embraced her role as a fighter to protect herself and her friends.

In the OVA *Dead Girls*, set 300 years in the future, Rose exhibits a dramatically different persona. Having lost her memories of her original life due to events surrounding the Animus and Dolore conflict, she now lives an immortal existence alongside Kate, Rachel, and Claire. The four share an apartment and work as bounty hunters while maintaining the facade of a normal school life. Rose has evolved into a confident and meticulous perfectionist, serving as chairman of "Grace," an elite student group. She leads reincarnations of Jessica and Paula, explicitly stating her desire to "be cool this time." Her demeanor mirrors Kate's former seriousness, and she adopts an elegant, fashionable appearance contrasting her earlier modest style. Rose suggests the group periodically relocate to experience new lives, indicating a strategic approach to their immortality. Prior to these events, her relationships included romantic ties to Agito Wanijima and a crush on Ben.