** spoiler alert ** 
 Fun book about a girl from the London slums who boards a British Navy boat as a boy. In my library it's a Young Adult book, but it's a good quick read, plenty of happenings and adventure. It's told first person, so it takes a little bit to get used to the grammar. A kid from the gutter's not going to speak the Queen's English, after all. 
 After surviving on the streets of London, Mary's friend and protector is killed. She takes his clothes and his shiv and heads off to find something more for herself. She can read and write (her parents had some means, before the rest of her family died from some illness) and is pretty scrappy. She's always dreamed of going to sea, so she boards a ship, no long Little Mary, but Jacky. 
 She thrives on steady meals and hard work. She faces battles, both with pirates and her shipmates, during which she earns her nickname "Bloody Jack." After a heated battle with a dreaded pirate in the Caribbean, the ship has to run itself ashore on an island or sink. Jacky is sent aloft on a kite to search for land and hardwood to repair the ship. She's swept off on the winds, finds woods, signals her ship and waits. Her rescue's imperiled when the pirates attack her shipmates. Her attempts to save them end her in a noose, with everyone knowing she's a girl. 
 They take the day, but she's put off the ship in Boston to attend a school for young ladies. 
 This is the first in a series. Maybe not great for younger kids.