A native of Oklahoma, Holmes moved to London in 1987 after completing her undergraduate and graduate work in Chicago. In London, she worked for the Liberal Democrats under Paddy Ashdown, including three years on the Northern Ireland portfolio (where she had lived in 1983 and 1985). During this time she was also an adviser to Lord Alderdice, Leader of the NI Alliance Party and sister party to the Liberal Democrats from 1987-1991. She became the Party’s national General Election Manager for both the 1992 and 1997 campaigns. 

After ten years, Holmes joined the BBC where, as Deputy Head of Corporate Communication Strategy, she helped launch BBC News 24 and BBC Online. Three years later Holmes was headhunted by Burson-Marsteller to advise clients such as Accenture on corporate social responsibility. In 2001, Holmes was recruited to be the Managing Director of the London office of the largest UK/U.S. business membership organization, BritishAmerican Business, Inc. and led the organization through the aftermath of 9/11, expanded their UK, EU and U.S. lobbying efforts and built up their communications and event program.

In 2005, she completed her PhD in International Relations at the London School of Economics. 

In 2006, Holmes became a speechwriter to Ambassador Robert H. Tuttle in London as well as a research Fellow at the Rothermere American Institute at Oxford University. After 21 years in London, Holmes was the Pierre Keller Fellow in Transatlantic Studies at Yale University for two years. In 2010, she returned to the UK briefly to be a consultant in the Liberal Democrat General Election Campaign resulting in coalition.  

Holmes received her PhD in International Relations and a Diploma (Distinction) in World Politics from the London School of Economics. She also holds an AM in Social Policy from the University of Chicago and a BS in Human Development and Social Policy from Northwestern University.