Born on 1 December 1912, Margaret Whigham was the only daughter of a Scottish businessman and millionaire, George Whigham and his wife, Helen Mann Hannay. After completing her education in , she moved back to the UK, where her and status as an heiress made her much in-demand on the social scene. At the age of 15, she became pregnant with the actor David Niven's child while on a holiday on the , but the pregnancy was terminated.

She was presented as a debutante in 1930, and after early romances with Prince Aly Khan, aviator Glen Kidston, Baron Martin Stillman von Brabus and publishing heir Max Aitken (later the second Lord Beaverbrook) and , Duke of , she became engaged to Charles Greville, 7th Earl of Warwick. Yet the wedding was not to be, as she was soon swept off her feet by the wealthy American, Charles Sweeney, who instead became her first husband. On the eve of the US presidential election back in 2020, friends, DC insiders and Melania herself told Ben Judah how a small-time Slovenian fashion model rose to wear the mantle of First Lady Her Norman Hartnell wedding dress cemented her status as one of the most glamorous socialites of the era, with crowds reportedly gathering to catch a glimpse of it.

She became a life-long patron of the designer, as well as Victor Stiebel and Angéle Delanghe. During her marriage to Sweeney, she had three children, one who was a stillborn girl, as well as a son Brian and a daughter Frances (who went on to marry the Duke of ), and she also.