Kieryn's mom put her into a recreational class at Rochester Gymnastics Academy in Rochester, NY when she was three years old and she has been there ever since! She was the 2015 Level 3 NY State All-Around, Vault, Uneven Bars & Balance Beam Champion, 2016 Level 4 NY State All-Around, Vault, Uneven Bars & Balance Beam Champion and 2017 Level 5 NY State All-Around, Vault, Uneven Bars, Balance Beam and Floor Exercise Champion. Kieryn was named to America's Top 100 in all three levels.

As a level 7 gymnast in 2018, Kieryn finished fifth in the all-around with a 37.400 and first on vault at the State Championships. She qualified to the Region 6 Championships, finishing first on vault, uneven bars, balance beam, floor exercise and in the all-around with a 38.425. She was named to America's Top 100 on uneven bars with a 9.800. Kieryn moved up to level 8 for the 2019 season where she took home gold medals on balance beam, floor exercise and in the all-around with a 38.475 at the State Championships. At the Region 6 Championships, Kieryn swept the gold medals with an all-around score of 38.975. Once again, Kieryn was named to America's Top 100 on uneven bars (4x), balance beam (3x) and in the all-around (2x). In November, Kieryn participated in USAG Developmental Invite Camp in Tennessee.

Kieryn moved up to level 9 for the 2020 season. She qualified to the State Championships but was unable to compete due to COVID-19 pandemic. However, she did place in America's Top 100 on uneven bars. Kieryn started off 2021 season by qualifying to HOPES pre-elite at the Buckeye National Elite Qualifier in Columbus, OH. In March, she swept the gold medals with an all-around score of 38.850 at the Level 10 State Championships. One month later, she took home gold medals on vault, uneven bars, balance beam and in the all-around at the Region 6 Championships. This qualified Kieryn to the Junior Olympic Nationals. On that same weekend, Kieryn also competed at the HOPES Classic in Indianapolis, IN where she placed second in the all-around and second on vault, uneven bars and floor exercise in the 13-14 age group. In May, Kieryn traveled to Daytona Beach, FL for the Junior Olympic Nationals where she placed ninth overall with a 37.450 and second on vault and balance beam out of 57 gymnasts. One week later, Kieryn returned to Indianapolis, IN for the HOPES Championships. She finished up her 2021 season with two gold medals on floor exercise and in the all-around and a silver medal on uneven bars. Kieryn was also selected to attend the USAG Developmental Camp multiple times throughout 2021.