After her degree from the University of Westminster and her Postgraduate Diploma from the Inns of Court School of Law, Magistrate Gunn was called to the Bar of England and Wales in 1998. She thereafter practiced criminal and civil law from chambers until in 2010 when she joined the Cayman Islands Government Legal Department as Crown Counsel. In 2010 she was admitted to the Bermuda Bar and became a Specialist Crown Counsel in the Director of Public Prosecutions office there. She was appointed a Magistrate in the Summary Court in 2012. In 2017 she was appointed as an Acting Grand Court Judge.