Hilary Erhard Duff (born September 28, 1987) is an American actress and singer. She began acting at a young age and rose to prominence as a teen idol, playing the title character in the television series Lizzie McGuire (2001–04) and its 2003 film adaptation. The success of the series led to roles in films such as Agent Cody Banks (2003), Cheaper by the Dozen (2003), A Cinderella Story (2004), and Cheaper by the Dozen 2 (2005). Duff has additionally appeared in numerous guest roles and appearances in television, including an award-winning recurring role on the third season of Gossip Girl as Olivia Burke, and the television film Beauty & the Briefcase (2010). In 2014, she landed a starring role in the upcoming TV Land sitcom Younger as Kelsey. Other than that, she has acted in several independent films