Greaves started 2018 as a Level 10 gymnast. She competed at the Nastia Liukin Cup where she finished 8th in the all-around. A week later she competed at the KPAC Elite Qualifier where she earned a score 51.650 and qualified as a junior elite. In early July, Greaves competed at the American Classic where she placed fourth in the all-around behind Kayla DiCello, Konnor McClain, and Skye Blakely but first on the uneven bars. Later that month she competed at the 2018 U.S. Classic where she placed ninth in the all-around and third on floor exercise. In August Greaves competed at the 2018 U.S. National Gymnastics Championships, her first ever National Championships. She finished sixth in the all-around and as a result she was added to the Junior National Team.