McKenzie began gymnastics at the age of two. In 2018, she competed at the U.S. Classic, where she placed 12th in the all-around. In 2019, she won the U.S. Junior Women's all-around title. She also competed at the Junior Pan American Championships, where she won a team gold medal and placed fourth in the all-around.
In 2021, McKenzie won the City of Jesolo Trophy all-around title. She also won the U.S. Junior Women's all-around title for the second time. She was selected as a member of the U.S. team for the 2021 World Championships, but she withdrew from the team due to an injury.
In 2022, McKenzie competed at the U.S. Classic, where she placed sixth in the all-around. She also competed at the U.S. Championships, where she placed third in the all-around. She was selected as a member of the U.S. team for the 2022 World Championships, but she withdrew from the team due to an injury.
McKenzie is known for her powerful tumbling and her elegant artistry. She is also known for her consistency and her ability to perform under pressure. Her signature skill is a double-twisting Yurchenko vault. She is also known for her strong bars and beam routines.