Hewitt was born in Waco, Texas, the daughter of Patricia Mae (née Shipp), a speech-language pathologist, and Herbert Daniel Hewitt, a medical technician.Hewitt grew up in Nolanville, Texas; after the divorce of her parents, Hewitt and her only sibling, Todd Hewitt, were brought up by her mother. Her first name was given to her by her brother, after a girl he was fond of as a youngster, while her middle name, "Love", was given to her by her mother after her best friend in college.

As a young girl, Hewitt was attracted to music which led to her first encounters with the entertainment industry. At the age of three, she sang "The Greatest Love of All" at a livestock show. Just a year after that, at a restaurant-dance hall, she entertained an audience with her version of "Help Me Make It Through the Night". By the time she was five, Hewitt already had tap dancing and ballet in her portfolio. At nine, she became a member of the Texas Show Team (which also toured in the Soviet Union). At the age of ten, at the suggestion of talent scouts, she moved to Los Angeles, California, with her mother to pursue a career in both acting and singing.