Diane was born in the Isle of Man, British Isles. She graduated high school in 1980. In 1981 she continued her studies in accountancy at Leeds, UK, where she also commenced the professional examinations of the Chartered Association of Certified Accountants. From December 1984 to July 1986 she worked for a large local firm of Chartered Accountants in Leeds. In July 1986 she moved to Cyprus with her family. From April 1987 to December 1990 she worked for the Nicosia member firm of Grant Thornton International, as an audit senior in the offshore companies department. During this period she completed her professional examinations and qualified as a member of the Chartered Association of Certified Accountants in 1989. In January 1991 she joined a large International Banking Unit, as the Financial Controller, where she stayed until December 2000.

In January 2001, Diane joined the UHY Group as a manager of the audit department, specialising in the provision of accounting, auditing and consultancy services to international businesses. In 2007 she was made Director of the auditing and assurance services of UHY Antonis Kassapis Limited, with responsibility for all audit and assurance services. Diane is also a member of the Cyprus Institute of Certified Public Accountants (ICPAC) and speaks fluent English and Greek.