Diana is a Guernsey Advocate. She is also a Fellow of ICSA, a Chartered FCIS and a Freeman of the City of London.
Diana joined the Commercial Relations Department of the States of Guernsey as a graduate trainee in 1986. The Commercial Relations Department became the Guernsey Financial Services Commission and she worked on introducing the new financial legislation that was being brought in to regulate the finance sector in the Island. Whilst at the Commission, she edited the Guernsey Company Law and Trust Handbook.
Diana joined the Channel Islands Stock Exchange in 1998 and assisted in its set up. Over the years she headed first the Membership Department and then the Corporate Affairs Department. In 2013 the business of the Exchange was restructured and she was appointed CEO of the Channel Islands Securities Exchange Authority Ltd, which is now the International Stock Exchange Authority Ltd.
Diana set up Pollet Chambers LLP with her husband Advocate David Thompson in January 2018. The firm's focus is in commercial, regulatory and criminal law. Diana is also a Notary Public.