Stiles was born on June 20, 1979 in Massachusetts and was later raised in New Hampshire. As a child, she attended Strafford Elementary School. After middle school, Stiles began her high school career at Coe-Brown Northwood Academy in New Hampshire. Growing up, Sarah aspired to be a performer but also had the dreams of being a fashion designer. She then decided that if she ever found time in the Future, she would pursue a career in fashion designing.