Hannah James and Kate Burton have been cast as relatives of Supergirl's Nia Nal (played by Nicole Maines), according to Deadline. James will reportedly play Nia's older sister Maeve while Burton will play their mother, Isabel.
"James’ Maeve Nal is driven and focused on maintaining the Nal family’s rich legacy. She and Nia have a strong sisterly bond, although Maeve has always had to work harder to achieve what comes naturally to Nia," reads Deadline's description of the two roles. "Burton’s Isabel, the warm and nurturing mother of Nia Nal, is a local hero in her own right. She is a wise and generous matriarch and has raised her family to be bold and courageous, as well as to love fiercely and openly."
Supergirl producers have said that Nia Nal will grow to become a superhero, taking the name "Dreamer", eventually on the show.
James is best known for her roles in PBS' Mercy Street and Starz's Outlander.
Burton is a three-time Emmy nominee, known for her roles as Vice President Sally Langston in ABC's Scandal and Ellis Grey in ABC's Grey's Anatomy.
Supergirl airs Sundays on the CW.