Article continues below advertisementWhat Is the 'Supergirl' Film About?Source: MEGAMilly Alcock appeared as Supergirl in the 2025 film 'Superman.'The new Supergirl will soar through the sky soon.Based on the Supergirl: Woman of Tomorrow comic book arc, the upcoming Milly Alcock-led film, Supergirl, will reportedly highlight the difference between the character and Superman.