Directors and casting decisions for the Supergirl project are described in coverage from multiple outlets. Craig Gillespie, who directs, discusses choosing Milly Alcock for the role and explains that the process involved both creative fit and the actor’s impact on the production. Across reports, Gillespie is quoted as seeing a “punk” quality in Alcock that aligned with the character’s tone and energy. The articles also mention that playing Supergirl affects Alcock personally, with some accounts describing nightmares she experiences connected to taking on the role. Taken together, the reporting emphasizes that Alcock’s performance qualities and the director’s view of the character’s attitude were key factors in the casting. While the outlets differ in how much detail they provide, they share the same central points: Gillespie identifies a specific stylistic trait in Alcock that supports the casting decision, and Alcock experiences unsettling dreams related to portraying Supergirl.