 In 2013, Strallen originated the role of Cassie in the West End revival of "A Chorus Line", which opened at the London Palladium in February 2013 and closed on 31 August 2013, and was directed by the original choreographer Bob Avian.Later in 2013, Strallen appeared in the Menier Chocolate Factory production of "Candide", where she played the role of Cunegonde from 23 November 2013 to 22 February 2014.She has also performed in the ensembles of the West End productions of "Chitty Chitty Bang Bang", "The Witches of Eastwick" and "Mamma Mia!