Hilary Erhard Duff born September 28, is an American actress, businesswoman, singer-songwriter, producer, and writer. Duff began her acting career at a young age and quickly became labeled a teen idol as the title character of the television series Lizzie McGuire — and in the theatrical film based on the series, The Lizzie McGuire Movie She later began appearing in independent films playing a wider range of roles, such as an oversexed popstar in War, Inc. She has also executive produced several of the projects she starred in, such as According to Greta , Beauty and the Briefcase and The Haunting of Sharon Tate. Since , she has starred as Kelsey Peters on TV Land 's longest-running original comedy-drama series Younger , for which she has received nominations for People's Choice Awards in and