As a student at Oviedo High School, Simpson was a 5-time state champion in track and 3-time state champion in cross country. She also set Florida high school records in the mile, two-mile, 5000 m, and three-mile. Jen finished 3rd in San Diego's Foot Locker Cross Country Championships in 2003 behind winner Katelyn Kaltenbach of Colorado and Marie Lawrence of Nevada. Barringer came on strong and won for the second straight year in identical times of 17:27, becoming the first Florida girl to ever win the Footlocker South regional twice. Jen finished 10th in San Diego's Footlocker cross country national championship in 2004.