Who is Luke’s twin sister?

The story behind the answer

Born to Anakin Skywalker and Padmé Amidala, Leia and Luke were separated at birth to be hidden from Darth Vader and the Emperor; she was adopted by Bail and Breha Organa of Alderaan, with the familial reveal arriving in Return of the Jedi. Padmé is their mother, not a sibling; Mara Jade is Luke’s later love interest in the Legends timeline, not canon to the films; and Ahsoka Tano is Anakin’s former Padawan.

Story context: Leia’s royal upbringing and political savvy set her on a path as a Rebel leader, while subtle Force connections foreshadow the truth—she senses Luke in The Empire Strikes Back—before training later resumes in the sequel era.