Kelly's West End musical credits include Beauty and the Beast, Whistle Down The Wind as Swallow (2000)(with a ten year old Jessie J), Les Misérables as Eponine at the Palace Theatre (2001), Mamma Mia! as Sophie at the Prince Edward Theatre (2002), and My Fair Lady as Eliza at the Theatre Royal, Drury Lane (2003). She made her Broadway debut in a revival of Fiddler on the Roof as Hodel (2004).