Dr. McDermott received her BDS in 1984 from the University of Leeds. She practiced dentistry in England and the Northwest Territories in Canada, and received her MSc DOrth in 1996 from the University of Manitoba, Winnipeg, Canada.

She owned her own dental practice in Yellowknife, Northwest Territories for 11 years and from 1996 2002, she was employed by the Canadian government as the Orthodontist for Northwest and Nunavut Territories of Canada. Since 2002, she has been a Lecturer and Specialist Orthodontist at the University College Cork dental school and hospital.

She opened Harley Court Orthodontics in 2005 to continue serving the community and practicing her passion of orthodontics.