DC Studios have reportedly begun the casting process for their upcoming film Supergirl: Woman of Tomorrow, with House of the Dragon breakout star Milly Alcock among the candidates to play the titular superhero.

Alcock played the young Princess Rhaenyra Targaryen in the first five episodes of HBO’s Game of Thrones prequel series, and many fans were left disappointed when she was replaced as her character aged.

Supergirl: Woman of Tomorrow was first announced by DC Studios co-CEO James Gunn in January last year.

According to reports in Deadline, also in the running are CODA and Cat Person star Emilia Jones, as well as Meg Donnelly, who has already given voice to the character in the DC animated films Legion of Superheroes and Justice League: Crisis on Infinite Earths Part One.

When the film was unveiled as part of Gunn’s vision for a new, “unified” DC Universe, the Guardians of the Galaxy director said that the new movie would feature Superman’s cousin Kara Zor-El, “a very different type of Supergirl”.

“In our series we see the difference between Superman who was sent to Earth and raised by loving parents from the time he was an infant, versus Supergirl who was raised on a rock, a chip off Krypton, and watched everyone around her die and be killed in terrible ways for the first 14 years of her life, and then came to Earth when she was a young girl.

“She’s much more hardcore; she’s not exactly the Supergirl we’re used to seeing.”

The movie will be based on Tom King’s comic book series of the same name from 2022.

It is possible that, given Gunn’s intention to unify the films, Supergirl could make an early cameo appearance in the already-announced Superman Legacy, slated for release on 11 July 2025.

That film is currently in pre-production ahead of shooting this spring in Georgia. It will star David Corenswet (Clark Kent/Superman), Rachel Brosnahan (Lois Lane), Nicholas Hoult (Lex Luther), Skyler Gisondo (Jimmy Olsen) and Sara Sampaio, with Anthony Carrigan (Metamorpho), Isabel Merced (Hawkgirl) and Nathan Fillion (Guy Gardner/Green Lantern).

Last month, Gunn also announced a new TV spin-off from The Batman movie called The Arkham Project.

Director Matt Reeves’ Arkham Asylum project had been in development for some time, but Gunn took to social media to officially confirm the spin-off was happening and would be a part of the wider DC universe.

A fan asked Gunn on Threads If Reeves was working on more projects in the “Batverse”, according to Deadline, to which he replied: “Right now Matt is producing Arkham as a DCU series, so there’s just the two for now.

“Yes. We love Matt as a director and producer so he’ll be producing stories both within his The Batman universe and within the DCU.”