She was d of Sir Ivar Iain COLQUHOUN 8th Bt of Luss 1916-2008 and Kathleen Nimmo 1922-2007 d of Walter Atholl DUNCAN 1874-1932 and Clara Ray 1889-1966 adopted d of John Henry PARKS 1849-1926 of Massachusetts and d of his 2nd w Elizabeth Ray PARKER 1873-. She m 1964 the 12th Duke of ARGYLL 1937-2001 s of the 11th Duke of ARGYLL 1903-73 and his 2nd w (her 2nd h, her 1st was Hon Andrew Vanneck gs of 3rd B Huntingfield) Louise Hollingsworth Morris 1905-70 d of the American sculptor Henry CLEWS 1876-1937 (see below) and his 1st w Louise Morris GEBHARD 1877-1936, and had a son (the present 13th Duke) and a dau as above.
Extract from Henry Clews’ entry in Wikipedia:
Clews was born on April 23, 1876, in New York City to a reputable New York family that was well-connected in Newport society. He was a son of the English-born Henry Clews, a well-known and wealthy Wall Street investment banker, and Lucy Madison (née Worthington) Clews, a relative of U.S. President James Madison, and a direct descendant of American Revolutionary War brigadier general Andrew Lewis. His maternal grandfather, William H. Worthington, was a Union Army officer who died during the Civil War. One of Clews' aunts was married into the Vanderbilt family and another into the Astor family.
https://www.findagrave.com/memorial/7792567/henry_clews
The Dowager Duchess of Argyll obituary, chatelaine of Inveraray Castle
Skilful embroiderer and gardener who played her part for the benefit of American tourists
Iona Campbell was at one time one of four duchesses of Argyll walking this earth, having married into the family in 1964. The previous year her father-in-law, the 11th Duke of Argyll, had been involved in an infamous divorce case with his third wife, Margaret... In time Campbell became chatelaine of Inveraray Castle, which the eighth duke had aggrandised with four “witches hats” perched on four corner towers to impress Queen Victoria on her visit in 1874…
…Iona Mary Colquhoun was born in Edinburgh in 1945, the second child of Sir Ivar Colquhoun Bt and his wife Kathleen (née Duncan). Her older brother, Torquhil, died in 1963 aged 19 and she is survived by her younger brother, Sir Malcolm Colquhoun Bt, the present chief of the clan Colquhoun. She was raised at Rossdhu House, on the west bank of Loch Lomond, near Luss in Dunbartonshire, and educated in Malvern, Worcestershire, before finishing schools in Paris, Florence and Madrid.
In 1964 she cancelled her coming-out dance to marry Ian Campbell, then Marquess of Lorne and heir to the 11th Duke of Argyll. He had known her since she was seven as “the girl who lived over the hill”, but had since been away in the army. Upon his return they met again at a cocktail party and he proposed that night. “You stupid man,” she replied. He went on to propose every night for a month until eventually he wore her down and she accepted.
Their marriage took place at St Giles’ Cathedral, Edinburgh, in the presence of 1,000 guests, uniting the Campbells of Argyll and the Colquhouns of Luss. The couple were piped out of the cathedral by the castle’s head gardener to the tune Iona’s Wedding, his own composition. Four years later the 11th duke left for Paris and the young couple took over the running of Inveraray, by the shores of Loch Fyne, where she enjoyed scuba diving.
In 1973 her husband, who was on the board of three distilleries, succeeded as the 12th Duke of Argyll. At the time his father’s widow and two of his former wives were still alive. He died in 2001 from heart failure during surgery in London aged 63. Later it emerged that he had left his wife only £100,000, with the £30 million estate placed in trust for his children for tax reasons.
“Anyone looking at Inveraray assumes you have a huge income,” she told The Mail on Sunday in 2002. “Well, my husband didn’t and neither did my father-in-law. That’s the way it is, and to keep the house we have to make sure it pays its way, year after year.”
Campbell … is survived by their children, Torquhil, the 13th Duke of Argyll who at the time he succeeded was working in the whisky industry in Hong Kong, and Louise, with whom she shared the patronage of the ball. “Would I remarry?” the dowager duchess said a year after being widowed. “I’d have to love somebody an awful lot. Maybe I should get a toyboy…”
The Dowager Duchess of Argyll was born on June 22, 1945. She died on February 22, 2024, aged 78
https://www.thetimes.co.uk/article/iona-dowager-duchess-of-argyll-6h7s5b8p5