Sun Girl was a member of the Knights.

Sun Girl was Erika Nystrom's first superhero name, the one she used from teenage years until several years after she joined the Knights. She then changed her codename to Solar Queen.

Sun Girl's uniform was a white "cheerleading outfit" or "school uniform," as some of the press dubbed it, with a yellow sun symbol on the chest. Early on she wore a yellow sun face mask as well, to conceal her identity. But after joining the Knights, she dropped the mask and made her identity public. Sun Girl had the same abilities as Solar Queen.