Bloody Jack: Being an Account of the Curious Adventures of Mary "Jacky" Faber, Ship's Boy by L.A. Meyer

Orphaned by the London plague of 1797, Mary Faber survives by joining a street gang. When her best mate is killed, she cuts her hair, changes her name, lies about her age, and secures a post as a ship's boy on the HMS Dolphin. Thus, the "Bloody Jack" series begins... with its impulsive heroine continually surrounded by challenges that cannot quench her love for adventure.