Hilary Erhard Duff (born September 28, 1987) is an American actress, singer, songwriter, designer, producer, and author. Duff began her acting career at a young age and quickly became labeled a teen idol as the title character of the hit television series Lizzie McGuire (2001–2004) and in the theatrical film based on the series, The Lizzie McGuire Movie (2003). Thereafter, Duff appeared in numerous films, with leading roles in Agent Cody Banks (2003), Cheaper by the Dozen (2003), A Cinderella Story (2004), and Cheaper by the Dozen 2 (2005). After experiencing commercial and critical failure in Material Girls (2006), Duff began appearing in independent films such as War, Inc. (2008), According to Greta (2009), and The Haunting of Sharon Tate (2019). She was also an executive producer on the latter two films. Since 2015, she has starred as Kelsey Peters on the TV Land comedy-drama series Younger, for which she has received nominations for People's Choice Awards in 2016 and 2017.