The senior Evans served as personal physician to Rufus Isaacs, 1st Marquess of Reading, during the latter's term as Viceroy of India (1921–26).

MacMillan received a Bachelor of Arts (BA) degree in history from the University of Toronto, where she attended Trinity College.

[13] In 2017, Prime Minister of the United Kingdom Theresa May advised Queen Elizabeth II to appoint MacMillan as a Member of the Order of the Companions of Honour.

She was chosen by Queen Elizabeth II and made a member of the Order of Merit by King Charles III in 2022.

Examples in 2014 include her retrospective trip to Sarajevo on the centenary of the assassination of Archduke Franz Ferdinand,[17][18] and interview wherein she saw similarities between then and 100 years before, remarked on the annexation of Crimea by the Russian Federation and her perception that Vladimir Putin deplored Russia's place in contemporary politics, mentioned Iraq and the contention between China and Japan over the Senkaku Islands, and promoted the diplomatic corps.

In December 2013, they abridged an essay of hers from the Brookings Institution,[21] in which she wrote that "Globalization can have the paradoxical effect of fostering intense localism and nativism, frightening people into taking refuge in small like-minded groups.

Globalization also makes possible the widespread transmission of radical ideologies and the bringing together of fanatics who will stop at nothing in their quest for the perfect society", and urged Western leaders to "build a stable international order" based on "a moment of real danger" which would unite the population in "coalitions able and willing to act".

[22] On the ten-year anniversary of the 11 September attacks in New York, MacMillan wrote an essay on the consequences of the attacks, in which she dismissed the power of Osama bin Laden and stressed the secular nature of the Arab Spring revolutions that deposed Hosni Mubarak and Zine El Abidine Ben Ali.

[23] In August 2014, MacMillan was one of 200 public figures who were signatories to a letter to The Guardian opposing Scottish independence in the run-up to September's referendum on that issue.