Marley grew up in Eagle Rock, California. Her mother, Carol, was a teacher and former singer and her father, Christopher Shelton, worked as a director and producer. She has three sisters: Koren, Erin, and Samantha. Both of her parents were involved in local theater projects, but as a teen, Marley was never interested in life on the stage. While at Eagle Rock High School, she was a varsity cheerleader, was voted Prom Queen and held part-time jobs at stores like Contempo and Wet Seal.