Abigail was born in Tampa, Florida to business owners Michelle and Eric Shapiro. She attended the Community Montessori School from two years old up until seventh grade. When she was 6 years old, she joined an all-girls singing and dancing ensemble called Entertainment Revue which performed across the state of Florida. At 12 years old, after her first professional audition, she booked the role of Cindy Lou Who in How the Grinch Stole Christmas the Musical at Madison Square Garden and moved to NYC thus began her professional career.