Jefferson attended Nimitz High School in Houston, Texas, where she was a three-sport athlete, playing softball, volleyball and basketball.

During her first year in 2018, she led the Longhorns in batting average (.392), hits (74), multi-hit games (23), runs (30), total bases (87), on-base percentage (.463) and steals (11).

[2] During her second year in 2019, she led the Longhorns in batting average (.408), hits (80), multi-hit games (25), and runs (39), and ranked second in on-base percentage (.438) and stolen bases (10).

[3] During the 2020 season, she Started all 27 games while batting .554 overall to rank third in the f NCAA Division I and first in the Big 12 Conference, and ranked tied for fourth in NCAA Division I and led the Big 12 in total hits (41), in a season that was shortened due to the COVID-19 pandemic.

She also ranked second in the Big 12 in batting average (.431), third in runs scored (70), fourth in steals (16) and total bases (131) and fifth in on-base percentage (.502) during the regular season.

[9] She finished her career at Texas as the program's record holder in batting average (.424), games started (269), runs (222), hits (362) and doubles (55).

[10][18] On January 7, 2022, she was named a member of the United States women's national softball team for the 2022 World Games.

[19][20] In the gold medal game against Japan, with the bases loaded and two outs in the bottom of the second inning, Jefferson hit a bases-clearing double to left-center field to give USA a three-run lead, and help USA win a gold medal.

[23] Jefferson represented the United States at the 2024 Women's Softball World Cup and won a silver medal.