[9] In 2017, Alcock landed her first named roles as Isabella Barrett in the web miniseries High Life alongside Odessa Young and Cindi Jackson in the third and final series of the ABC Television drama Janet King.

[6][8] In July 2021, it was announced Alcock had been cast as young Princess Rhaenyra Targaryen (later played by Emma D'Arcy) in the 2022 HBO fantasy series House of the Dragon, a Game of Thrones prequel and adaptation of George R. R. Martin's fictional history book Fire and Blood.

She's got an enchantingly expressive face – a simple squinting of the eyes or a pursing of the lips can betray the range of emotions that accompany king's court politics.

"[21] For the role, Alcock received a nomination for Critics' Choice Television Award for Best Supporting Actress in a Drama Series.

[2] In January 2023, Alcock appeared in the music video for the song "Easy Now" by Noel Gallagher's High Flying Birds from the band's fourth album Council Skies.

[24][25] She will star alongside Julianne Moore and Meghann Fahy in the Netflix dark comedy limited series Sirens.