Lark was a finalist on I'd Do Anything on BBC One from March to May 2008, a show which searched for a new, unknown lead to play Nancy in a West End revival of the British musical Oliver!.
Immediately after the show Lark participated in the I'd Do Anything tours with fellow contestants Ashley Russell, Keisha Amponsa-Banson and Niamh Perry, along with Michael French and Connie Fisher, accompanied by the BBC Singers and the BBC Symphony Orchestra.