As a member of Ireland's most famous dynasty, she celebrated her 70th birthday with a lavish party at the Guinness Storehouse in Dublin.
That was last August despite Miranda Guinness's ongoing battle with cancer.
"I have to admit, it's been a privilege to be part of this family," she said. "I'm very much at home in Dublin."
The former socialite died in England yesterday at the age of 70, after a long illness.
Mrs Guinness, the Countess of Iveagh, married Benjamin Guinness, the third Earl of Iveagh, in 1963. The couple had two sons, Edward and Rory, and two daughters, Emma and Louisa, before divorcing in 1984.
Benjamin Guinness -- direct descendant of Arthur Guinness -- lived at Farmleigh and was chairman of the famous brewery from 1961 until his death in 1992.
Following the couple's divorce, Miranda Guinness went on have a six-year relationship with the late Tony Ryan, founder of Ryanair.
After their break-up, the Countess bought Wilburry, a rundown mansion in Wiltshire, which she restored in a similar manner to the way Tony Ryan restored the Lyons Demesne in Kildare.
The one-time socialite, who worked as a PA for the Rolling Stones' Mick Jagger for many years, had kept a relatively low profile in recent times. But she did hit the headlines earlier this year when she put her red DeLorean coupe up for auction. "I love this car," she said at the time. "I have many happy memories of driving my sons to school in it. They weren't so positive about it since I had a knack of knocking myself out on the gull-wing door."
The famous DeLorean, which was built outside Belfast by the American car designer John DeLorean, was eventually sold to a Mayoman for approximately ?20,000.