[4] Guinness attended a finishing school in Paris, and went on a worldwide tour on her father's yacht called the Fantome with her parents and sisters after which she was debuted in society in 1925.

Her husband was killed in 1945 in Burma during World War II, leaving Guinness widowed with three young children.

[1][5] Guinness was known for her unusual sense of fashion, and is believed to have provided inspiration for Barry Humphries’ character Dame Edna Everage and Osbert Lancaster's Maudie Littlehampton in The Daily Express.

She later became active in charitable work, raising £50,000 between 1958 and 1965 to build the Horder centre for arthritics as well as donating the site in Sussex.

She stood down from this committee due to a disagreement, but she later opened Maureen's Oast House in 1996, as a holiday home for arthritics on her Kent estate.

Her daughters and daughter-in-law unsuccessfully contested in court Guinness's passing of assets worth £15 million directly to her two grandchildren in 1995.