Supergirl is Kara, a survivor from Krypton's neighboring planet. Superman adopted her as his cousin and she joined him in his mission to protect Earth and promote peace. She eventually joined him in the Justice League when it expanded and had several adventures on her own as well as with other leaguers- even facing off against her clone GalateaFearful Symmetry, and traveling to other worlds Chaos at the Earth's Core and even the future Far from Home. As she grew older however, she found she had to forge her own destiny and stayed in the future.