Kelsey grew up skiing at Gore Mountain and spent her summers surfing in New Jersey with her family, who described her as always "being fast and fearless." In 2019, she graduated from State University of New York (SUNY) Adirondack and became a registered nurse, living out her dreams of helping others and making a positive impact. On a day of sledding with her family in 2021, O'Driscoll sustained spinal fractures, which left permanent damage, and she had to relearn how to walk. She was determined to return to nursing and, along the way, relearned her love of skiing as a four-tracker.

O'Driscoll went on to become Gore Mountain's first adaptive ski patroller and quickly showed promise early in her ski racing career. She was quickly recruited by the National Sports Center for the Disabled to train with their team, and she continued to impress. In 2025, O'Driscoll made her FIS Para Alpine World Ski Championships debut, where she finished sixth in slalom and eighth in giant slalom in a stacked field. During the 2025-26 season, Kelsey made her World Cup debut and has since earned two World Cup podiums and a win. She was named to the 2026 Paralympic team and raced in all five disciplines.