Hannah started gymnastics at the age of two because she wanted to be like her older sister. She loved the challenge and learning new tricks and was able to keep up with older girls in her classes. She started her competitive gymnastics career at Apex Athletics in St. James, NY. She was the 2015 Level 4 NY State Vault and Uneven Bars Champion. Hannah was named to America's Top 100 in level 4.

In 2018, Hannah placed fifth in the all-around and second on balance beam at the Level 8 State Championships. She qualified to the Region 6 Championships, finishing fourth in the all-around and fifth on uneven bars. As a first-year level 9 gymnast in 2019, Hannah qualified to the Region 6 Championships where she finished in the top ten in the all-around. She qualified to the 2020 Level 9 State Championships but was unable to compete due to COVID-19 pandemic.

When Hannah isn't busy training 22 hours each week in the gym, she enjoys hiking, biking, hanging out with her friends and playing viola. Hannah is the youngest of three children to Stacey and Marc Gerstein. She has one older sister, Mikayla, one older brother, Brandon, a dog named Bella and two Russian Siberian cats. Currently, Hannah is a student at Smithtown High School East and she will graduate in 2024.