In 2014, she appeared in the film Paddington, beating more than 100 competitors for the role. She stars in the film alongside Hugh Bonneville, Sally Hawkins, Julie Walters, Jim Broadbent, Peter Capaldi, and Nicole Kidman. Harris played Judy Brown, the daughter of the family with whom Paddington lives, and later reprised the role in the sequel Paddington 2.
As of 2014 Harris still attended school, and manages to combine her school work and her acting jobs. Harris also likes other artistic disciplines. She has enjoyed writing her own stories since she was young.