In the first season, Kara is forced to reveal her powers, and becomes National City 's protector. Kara discovers that hundreds of the criminals her mother imprisoned are hiding on Earth, including her aunt Astra and Astra 's husband Non. Kara works with her adoptive sister Alex Danvers to fight these criminals, alongside the Green Martian J'onn J'onzz, her cousin 's friend James Olsen, and tech genius Winn Schott, Jr.
what city does supergirl protect in the show
National City