While in sixth form Lewis made her television debut in the fifth series of E4's teen drama Skins, which started on 27 January 2011. She gained the role of Liv Malone through open auditions in Bristol. Members of the shows production team visited some of the local schools and she was asked to attend and audition. At the age of 16 she auditioned for the second generation of Skins, however when she arrived she decided not to participate.

In April 2012, Lewis starred in Emeli Sandé's music video "My Kind of Love", directed by Dawn Shadforth. It recounts the story of the ambiguous relationship of two female characters, and how the younger girl, played by Lewis, lives with cancer. In 2013 she filmed The Line, a short movie written and directed by BAFTA nominated Faye Gilbert about a teenage girl and young boy running for their lives in a Futuristic world. Next Lewis will play the lead role of Beverly in Beverley, a short film produced by Cass Pennant telling the true story of a mixed-race girl growing up in the city of Leicester in the 1980s.

In 2014, she appeared as Potato Girl in Cuckoo.