She also represented the United States at the 2019 FIBA Under-19 Women's Basketball World Cup and won a gold medal.

Hillmon averaged 21 points, 14 rebounds, 2.7 blocks and 2.0 steals per game as a senior to help lead the Lancers to their first OHSAA Division III state championship, after winning back-to-back district and regional titles.

[1] She became the fourth girls basketball player in state history to score 2,000 points in a high school career.

[2] Hillmon verbally committed to play basketball at Michigan on July 4, 2017, following her graduation from Gilmour Academy.

Hillmon ranks fourth nationally in scoring at 25.1 points per game while coming in second in field goal percentage (.648), 17th in rebounding (11.3) and 26th in double-doubles (10).

Hillmon averaged 21.0 points, 9.6 rebounds and 2.2 assists in 33.5 minutes per game, and recorded 17 double-doubles, to move into first place all-time at Michigan.

[27] She was also named a first-team All-American by WBCA, USBWA, The Athletic, Sports Illustrated and the Wooden Award.

She finished her career at Michigan as the program leader in rebounds (1,063), double-doubles (52) and free throws made (487).

[28] On March 29, 2022, Hillmon renounced her extra year of eligibility due to the COVID-19 pandemic and declared for the 2022 WNBA draft.

Hillmon represented the United States at the 2019 FIBA Under-19 Women's Basketball World Cup where she was team captain.

During the tournament, Hillmon recorded one double-double, and averaged 11.8 points, 7.8 rebounds and 1.5 assists in 21.5 minutes per game, to help lead USA to a gold medal.