'Supergirl' Casts Dreamer's Mom and Sister for Season 4

Family is a centerpiece of Supergirl, but it sounds like Alex and Kara won't be the series' only sister act for long. The CW has cast Nal Nal's sister and mother for the series.

According to Deadline, Outlander alum Hannah James is set to recur as Nia's (Nicole Maines) older sister Maeve, while Scandal and Grey's Anatomy alum Kate Burton will guest star as her mother, Isabel.

Maeve Nal is described as being a driven young woman focused on maintaining her family's rich legacy and while she's always had to work a little harder for her achievements than Nia, the sisters are described as having a very strong bond. As for their mother, Isabel, she is described as being a local hero in her own right who raised her family "to be bold and courageous, as well as to love fiercely and openly."

It will be interesting to see how Nia's family factors into this season and what role they will play -- if any -- in her transition into the hero Dreamer, a character poised to be television's first transgender superhero. It will also be interesting to see if the show's anti-alien storyline will be a factor, both with the Nal family and Nia's heroics.

Supergirl's character is based on Nura Nal, the Legion of Super-Heroes member initially known as Dream Girl in comics. Created by Edmond Hamilton and John Forte in 1964, Dream Girl was an alien with precognitive abilities. The Dreamer identity debuted in 1996 in a story by Tom Peyer, Tom MCGraw, and Lee Moder. If Nia is of alien origin, standing up for others may well be what propels her into heroics beyond her work at CatCo.

Whatever the reason Nia becomes Dreamer, Maines told reporters during a visit to Supergirl's set that she's very excited to suit up.

"I'm so excited," Maines said. "I'm trying to conduct myself on set in a professional manner and be like 'I'm not completely obsessed with the super-suit,' but it's all I think about. Every morning I wake up, 'I'm getting a super-suit!' I'm going to sleep, 'I'm getting a super-suit!' I'm really, really excited. It's gonna be gorgeous! I have the best super-suit. I do."

Supergirl airs Sundays at 8 p.m. ET on The CW.