Mrs. Johnston is the Head of Corporate Services at Jamaica Producers Group Limited and is the Honorary Consul for the Republic of Costa Rica. She is a director of The Gleaner Company (Media) Limited and is a member of the Corporate Governance and of the Finance, Compliance & Audit committees of the Board.
Mrs. Johnston is the chairperson of the St. Mary Education Trust. She is also a Director and former Vice President of the Jamaica Manufacturers & Exports Association and serves on the boards of the Consular Corps of Jamaica, and JP Tropical Group. She is a member of the Jamaica Trade Policy Advisory Group (formerly JTAT) in the Ministry of Foreign Affairs and Foreign Trade and of the Food Security & Agribusiness Council (a joint committee of the Ministry of Agriculture & Fisheries, the Ministry of Industry, Investment & Commerce and the private sector). Mrs. Johnston was a Galo Plaza Fellow at the Inter-American Dialogue in Washington D.C. and a former freelance columnist of The Gleaner newspaper.