big sister (noun)

1. During the American Revolution, the big sister played a crucial role in supporting her family and the cause of independence.

2. In Greek mythology, Athena was the big sister of Perseus and she provided guidance and protection to him throughout his heroic quests.

3. Wonder Woman's alter ego, Diana Prince, is a big sister who fights alongside Batman and Superman to protect the world from evil forces.

4. In Louisa May Alcott's novel Little Women, Meg March serves as the responsible and caring big sister who takes care of her younger sisters.