[4] She joined the Richmond Academy of Dance in 2012, through which she auditioned for and earned a scholarship to attend the Sylvia Young Theatre School.

[5] Amarteifio made her West End debut as young Nala in The Lion King at the Lyceum Theatre in 2011.

Amarteifio was in the 2013 original cast of Charlie and the Chocolate Factory at the Theatre Royal, Drury Lane in the alternating role of Violet Beauregarde.

In 2022, she played Nora Randall in the Sky Max science fiction series The Midwich Cuckoos.

[10] The following year, she starred in the leading role of a young version of Golda Rosheuvel's titular character in the Netflix period drama prequel Queen Charlotte: A Bridgerton Story.