In 2018, Son was approached by director Sean Baker outside a screening of Gus Van Sant's Don't Worry, He Won't Get Far on Foot at the Arclight Hollywood Cinema. Baker asked her to audition for his upcoming film but did not call her back for two years.[3] The film, Red Rocket was released in 2021 and featured Son in a major role as a 17-year-old girl in South Texas who gets into a relationship with a former porn star, played by Simon Rex. The film was her first feature role; prior to Red Rocket, Son had appeared in a "risque" low-budget short film.[3][4] Son was nominated for a Gotham Awards for Best Breakthrough Performer[5] and an Independent Spirit Award for Best Supporting Actress for the role.[6]
Son has also released music recordings, chiefly through uploads to her YouTube channel.[7] When Baker discovered that she taught piano, he wrote a scene for her in the film in which she sings a slow ballad cover version of the NSYNC song "Bye Bye Bye". Son also performed an original song in case they were unable to secure the rights to the song, but all five members of NSYNC approved of the cover.[8] Son's version was released on various music streaming services to promote the film.[9][10][11]
In November 2021, Son joined the cast of the HBO music-industry drama series The Idol opposite The Weeknd and Lily-Rose Depp.[12] On April 27, 2022, Deadline reported that she was one of the cast members not expected to return after a forced hiatus, due to a change in the show's creative direction,[13] although Son appeared in the official teaser trailer released on August 21, 2022.[14] On March 1, 2023, Rolling Stone reported that Son remained in the cast despite the overhaul.[15]
