Early in the film, Thatcher and her husband are at a performance of Norma at Covent Garden in London. The date on the program is 1950, and Maria Callas plays Norma. Callas did not debut in London until 1952, and the recording of Callas used in the film was recorded in 1954.
One shot, set in the 1980s, shows the Houses of Parliament from Westminster Bridge. To the right, a National Express coach on Westminster Bridge has 'high level' brake lights, which first appeared on busses in the late 1990s, and a 2011 livery.
In 1990, her final year as Prime Minister, Thatcher refers to the European Union. At that time it was known as the EEC (European Economic Community) or, less formally, the European Community. It became the European Union in 1993, when all member countries ratified the Maastricht Treaty.
In the film, Labour leader Michael Foot opposes the decision to send a task force to the Falkland Islands, and Margaret Thatcher admonishes him in the House of Commons following Britain's victory over Argentina. Charles Moore's authorized biography of Thatcher clearly states that Foot supported her on the Falklands, and she emerged from the conflict with renewed personal admiration for him, despite their profound disagreements on most political issues.
"Norma", the opera that Margaret and Denis watch in the theater and whose aria "Casta Diva" is widely used in the movie score, was composed by Vincenzo Bellini, not Francesco Bellini as the framed booklet says.
On several occasions when Thatcher is speaking in the House of Commons, the camera pans the house and no other female MPs are shown. The House of Commons had 19 female MPs in 1979, when Thatcher became Prime Minister, and 66 in 1992, just after she retired. In an article in the Daily Mail dated January 9, 2011, director Phyllida Lloyd said "I've deliberately put no other women in the shots. There were, in fact, 19 female MPs by the time she became Prime Minister but we are trying to show not how it was to the objective eye but how it felt from her point of view. Ours is a collection of very selective memories, of a life of a woman formed by the Second World War and permanently at war, her life played out as a series of battles."