Jennifer was born in Texas, the daughter of Patricia Ann (née English), an English teacher from Oklahoma, and Billy Jack Garner, a chemical engineer who worked for Union Carbide from Texas. She is the middle child between two sisters, Melissa Lynn Garner Wylie (born 1969, resides in Boston, Massachusetts) and Susannah Kay Garner Carpenter (born January 24, 1975 in West Virginia, resides in Charleston, West Virginia). Her family is Methodist.