Mamie Gummer. Actress: The Lifeguard. Mamie Gummer was born on 3 August 1983 in New York City, New York, USA. She is an actress, known for The Lifeguard (2013), Ricki - Wie Familie so ist (2015) and John Carpenter's the Ward - Die Station (2010). She has been married to Mehar Sethi since February 2019. They have two children. She was previously married to Benjamin Walker.