first appeared on the Channel 4 soap opera Hollyoaks on 12 September 1996, walking into the video shop in the forty-third episode. Mandy came into the village at the age of 14 as a "wannabe supermodel" and quickly formed a friendship with Ollie Benson. Sarah stayed on Hollyoaks for a decade leaving in 2006. Dunn has returned to Hollyoaks three times.
In February 2007 for a two episode stint for the funeral of Mandy's best friend, Becca Dean (Ali Bastian). Also June 2008 for six months leaving in December after the disastrous wedding of Warren Fox (Jamie Lomas) and Louise Summers (Roxanne McKee).
In November 2010 Dunn returned to Hollyoaks with a one year contract alongside Jamie Lomas as Warren Fox. She left in September 2011.