BURBANK, Calif. – Nicole Maines understands the significance of her new “Supergirl” character by imagining what someone like Nia Nal/Dreamer would have meant to her when she was a child.

“If I had had a trans superhero, someone who looks like me wearing a cape, (while) growing up, that would have changed the game. That would have been an entire new level of validation in myself to think that I can be a superhero!” says the 21-year-old trans woman, who joins the CW action series in Season 4's opener (Sunday, 8 EDT/PDT).

Nia, who is inspired by and an ancestor of 30th Century DC Comics character Nura Nal/Dream Girl, marks TV's first trans superhero. She's introduced as a young reporter working for Kara Danvers/Supergirl (Melissa Benoist) at CatCo Worldwide Media. Her identity, her superpower (Dreamer is an alien "precog" who can dream the future) and her icy-blue suit will be revealed as the season progresses.

Producers were committed to adding a trans hero to the DC Comics TV universe headed by megaproducer Greg Berlanti ("Arrow," "The Flash"), says executive producer Robert Rovner.

Nia’s identity as a trans woman is part of her origin story, adds executive producer Jessica Queller, and is connected to “why and how she’s inherited these powers.” As with Kara in Season 1, she will have to come to terms with her power.

Nia's role as a journalist is important, too, as "Supergirl" is "hoping to portray the press as heroic," Queller says.

After spending a significant part of Season 3 off-world, Kara/Supergirl & Co. are back in National City for the new season. Nia shows ambition and some youthful awkwardness, reminding Kara of an earlier version of herself.

The new character also meshes well with the upcoming season’s focus on a growing campaign against aliens, including superheroes, that's led by a charismatic leader, Agent Liberty. The allegory parallels timely discussions about immigration and acceptance of people regardless of race, ethnicity, sexual orientation or gender identity.

Maines says Nia's experience as an alien, like Supergirl, and a trans woman give her perspective on the treatment of marginalized communities. "It's very relevant to today."

In casting Nia, “we were looking for somebody who embodied the innocence, strength and intelligence of a young Kara, which was Nicole, who also happened to be a real-life superhero in our eyes,” Rovner says, referring to Maines' activism.

Long before being cast in "Supergirl," Maines was in the news as a winning litigant in a 2014 Maine Supreme Court case that gave people the right to use the bathroom of the gender with which they identify, a big advance for transgender rights.

During her childhood, Maines and her family faced extreme public scrutiny and harassment, leading parents Kelly and Wayne to move Nicole and her twin brother Jonas to a different school. Their story became the basis for Amy Ellis Nutt’s 2015 book, “Becoming Nicole: The Transformation of an American Family.”

Maines, who later enrolled at the University of Maine, became an accomplished public speaker, giving an impressive TED Talk while just a teen and speaking at schools about her family’s experience, including her father’s slow but loving acceptance.

“The TED Talk and ‘Becoming Nicole’ and being a public speaker has given me some notoriety to the degree that I was already prepared with how to interact with social media (and) negative comments,” says Maines, who was featured in the 2016 HBO documentary, "The Trans List."

But attention "exploded" after she was introduced in July at San Diego Comic-Con. Although there’s been some negative reaction to her "Supergirl" casting, it's mostly been positive. .

As for disapproving comments, “It’s the same that trans women, trans men face on social media every day, folks who don’t agree or don’t believe in this,” she says. But there’s been “an outpouring of love and support from fans of the show and from folks who don’t watch the show (and) are so excited to have someone who looks like them, not just on television, but wearing a cape (on TV). It’s so validating and empowering.”

Maines, who played a trans teen in an episode of USA’s “Royal Pains” and in “Bit,” an upcoming horror film about intersectional feminist vampires, says it’s important for trans actors to play trans characters.

When cisgender men play transgender women, it creates an image of "men wearing dresses" that can affect people's perceptions. “When we have trans actors play trans characters, people can look onscreen and say, ‘OK, this is what trans is.’”

Opportunities for trans actors are growing, in Amazon’s “Transparent,” Netflix's "Orange Is the New Black" and FX’s “Pose.” But they're still rare, and firsts are significant. However, that identity shouldn’t be all-defining for the character, and it isn’t for Nia.



"What’s amazing with Nia is we have a trans woman who has personality and growth outside her trans-ness. … She’s a reporter, a superhero, a trans woman. She has a personal life,” Maines says, adding gleefully: “Oh, Nia! How do you do it all?”