Before joining the SWA, Karen was a diplomat in the Foreign & Commonwealth Office for 16 years, where she held a variety of posts in London and overseas, including as British Ambassador to Morocco and non-resident Ambassador to Mauritania and Counsellor to the British Embassy in Washington.  She was also posted to the UK's Permanent Representation to the EU in Brussels and the British Embassy in Baghdad.

In London, she served in the Cabinet Office and the Joint Intelligence Committee, as well as in several roles in the Foreign Office. Before joining government, Karen was a lawyer at Clifford Chance, working in London and Hong Kong. Karen is currently an adviser to the UK Government’s Board of Trade.