In 2007, Nixon was cast by director Maria Aberg for the Royal Shakespeare Company in Roy Williams' Days of Significance which played at the Swan Theatre in Stratford-Upon-Avon before moving to the Tricycle Theatre in London.
Following the success of Days of Significance, Nixon worked at Shakespeare's Globe in London, where she was commended in the prestigious Ian Charleson Awards for her portrayal of Jessica in The Merchant of Venice.