Before she was cast for a significant role in Quentin Tarantino's the long-awaited ninth film, Julia Butters had no idea who Quentin Tarantino was. She also didn't know the names Leonardo DiCaprio and Brad Pitt, two of the 10-year-old actress's co-stars in Once Upon a Time in Hollywood. And though she's a relatively new face in movies (she's been acting in TV roles since she was even younger), Butters might be Hollywood's real star.