Following her breakout role as the young Rhaenyra Targaryen in House of the Dragon, a prequel to Game of Thrones, Milly Alcock is preparing to debut in yet another major franchise as she steps into the titular role of Supergirl in the upcoming film.Milly Alcock with Supergirl director Craig Gillespie in Mexico City in April. Photo: APSet to premiere on June 26, the DC film also stars David Corenswet – reprising his role as Superman – and Aquaman star Jason Momoa.Say hello to the brand-new Supergirl: Milly Alcock. Photo: APBefore landing the role of Supergirl, Alcock opened up in an interview with Vanity Fair, saying she had sworn off big franchises after House of the Dragon, but then started to panic when auditions dried up after she starred in Netflix’s Sirens.Milly Alcock in a scene from Supergirl – the young actress was also in Game of Thrones prequel House of the Dragon. Photo: AP“I was so s***‑scared that my life was over at 22,” the actress told Vanity Fair. So when the audition for Supergirl came along, the 26-year-old says, “I kind of bullied myself into it.”Here’s everything to know about Milly Alcock, the new Girl of Steel.She dropped out of high school to actMilly Alcock in 2018. Photo: @millyalcock/InstagramBorn in Sydney in April 2000, Milly Alcock was raised by a single mother who worked as a nanny. Growing up, Alcock idolised Australian actors including Cate Blanchett, Sarah Snook and Heath Ledger. She struggled with school and at the tender age of 13, started cold-calling talent agencies in hopes of landing herself an audition. Her first ever role was as an extra in a 2014 episode of the Australian TV romcom drama Wonderland.