Deirdre started dancing at the age of 4 with her Mother, Anna O’Sullivan. After quitting for 2 weeks, because she didn’t want to go to the ‘big’ line with Mom, she started again and never looked back. She won countless medals at local feisanna in both solos and teams while enjoying her time with her family and friends. Deirdre, along with her brother John and sister Annemarie, danced for the O’Sullivan School until 1977 when they all transferred to Jimmy and Pat Friel. Deirdre consistently placed in the top 3 at local, regional, and national championships in both solos and teams during her time with Jimmy, where she liked to keep things fun and interesting. Due to a family situation, Deirdre took some time off from dancing from 1984-1986. When she returned to dancing in 1986, Jimmy had closed his school, so she decided to join the Early-McLoughlin School, with Patsy and Jimmy, where her sister Theresa was a student. There, she continued to place among the best in solos and teams at local, regional, national and international levels, while still having fun with family and friends.
In 1992, while completing her Bachelors and Masters Degree in Physical Therapy at Thomas Jefferson University, she took her TCRG exam. She has since gone on to become a Doctorate in Physical Therapy. She is highly regarded for her professionalism and expertise as Pediatric Physical Therapist. In 1996, after establishing her career as a physical therapist working with multiply handicapped children, she re-opened the O’Sullivan School of Irish dancing with the assistance of her mother, Anna. Deirdre then passed the rigorous ADCRG exam in 2016 and has been asked to adjudicate at many feisanna throughout North America.