Kellyman appeared in
Raised by Wolves, written by
Caitlin Moran and her sister Caroline Moran for
Channel 4. She also appeared in the 2016
BBC sitcom
The Coopers Vs The Rest with
Tanya Franks and
Kerry Godliman, about a trio of adopted children raised by a suburban couple. Kellyman was cast as the marauder
Enfys Nest in
Solo: A Star Wars Story in 2018. The role of Nest in
Solo: A Star Wars Story has been reported as the "anti-hero we deserve" and "the most important new character introduced in the movie." This role was reported to have given Kellyman "global recognition". For the role Kellyman had to go through three stages of audition. Kellyman only tested with the lead of the film,
Alden Ehrenreich, during the third audition, doing both acting and stunt test work. Kellyman also appeared in the BBC's adaptation of
Les Misérables as
Éponine alongside
Olivia Colman,
Lily Collins,
David Oyelowo and
Dominic West. Kellyman had originally auditioned for the role of Cosette, but was called back for the role of Éponine. Kellyman appeared in
BBC Two dark comedy series ''
Don't Forget the Driver, starring Toby Jones. 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. Kellyman co-stars in the 2021 Disney+ action series The Falcon and the Winter Soldier as Karli Morgenthau, the leader of a radical group called the Flag Smashers, alongside Anthony Mackie and Sebastian Stan. Kellyman starred as knight-in-training Jade in the 2022 Disney+ series Willow; a sequel series to the 1988 film of the same name. The relationship between Jade and fellow series lead Kit, portrayed by Ruby Cruz, makes the series "the first true franchise on Disney Plus to really center a queer story," according to Polygon''. Kellyman plays Jimmy Ink/Kelly in the horror film
28 Years Later (2025) and its sequel
28 Years Later: The Bone Temple (2026). Kellyman plays the role of Madison Flynn, the Thought Leader and head of the Social Media Team in the 2026 BBC comedy series
Twenty Twenty Six. == Personal life ==