MacMillan joined the
Foreign and Commonwealth Office in February 1982, having previously worked as a translator in Paris. She served in British diplomatic missions in Mexico, the US, Chile and Nicaragua. MacMillan was made a member of the
Royal Victorian Order in the
2013 New Year Honours when she was deputy director of protocol and assistant
marshal of the Diplomatic Corps. Following the departure of
Vice Admiral Sir Adrian Johns in 2013, MacMillan was sworn in to assume the full powers of the governor. She once more served as interim governor from September 2015 when Johns' successor Lieutenant General
Sir James Dutton also left having resigned. ==References==