Die Republik der Backfische (1928)

The ridin', ropin' and shootin' Billie is shipped from the Argentinian pampas to Europe to be polished girls' boarding school. Cheerfully untamable, she constantly violates the rules of the boarding school and is thrown out. So she gathers other girls around her and founds the Republic of the Teenage Girls on a deserted island, and becomes its president herself.