An Illinois native, Fleming was a four-year starter at Lakes Community High School. The 2022 Female Athlete of the Year, Fleming was also named team captain as a senior. She was a First Team All-State and All-Conference honoree as a catcher. The catcher played travel ball for two seasons for the Nationals Premier.
Fleming was also a three-year starter for the Lakes Community basketball team, setting the career, game and season record for charges taken. She was a two-year starter on the varsity football team, becoming the first female to catch a pass in varsity competition in the conference. Fleming also started on special teams for the varsity team her senior year.