Kellyman was cast as the marauder Enfys Nest in Solo: A Star Wars Story in 2018.[3][4] The role of Nest in Solo: A Star Wars Story has been reported as the "anti-hero we deserve"[5] and "the most important new character introduced in the movie."[6] This role was reported to have given Kellyman "global recognition."[1] For the role Kellyman had to go through three stages of audition.[7] Kellyman only tested with the lead of the film, Alden Ehrenreich, during the third audition, doing both acting and stunt test work.[8]
Kellyman also appeared in the BBC's adaptation of Les Misérables as Éponine alongside Olivia Colman, Lily Collins, David Oyelowo and Dominic West.[9] Kellyman had originally auditioned for the role of Cosette, but was called back for the role of Éponine.[1] Kellyman praised the diversity in the BBC production, admitting she never considered she would be able to play such a role in a period drama.[10]
Kellyman appeared in BBC Two dark comedy series Don't Forget the Driver, starring Toby Jones.[11] In 2020, Kellyman played the role of Maya, a child that comes to live with her distant aunt, in the BBC TV drama series Life.[12]
Kellyman starred as knight-in-training Jade in the 2022 Disney+ series Willow; a sequel series to the 1988 film of the same name.[14] The relationship between Jade and fellow series lead Kit, portrayed by Ruby Cruz,[15] makes the series "the first true franchise on Disney Plus to really center a queer story", according to Polygon.[16]
