She was 68 and had suffered from a debilitating brain disease for six months.
She had sought seclusion to escape the pressure of being in the eye of a society storm following the collapse of her own marriages and then the dnouement of daughter Diana’s life.
Mrs Shand Kydd would insist she was happy with her frugal lot. Yet whoever saw her found it hard to reconcile the fragile and thin woman, who befriended only a few locals on Seil Island and in nearby Oban, with the vivacious debutante who was said to have entranced London in the Fifties.
It was also exceptionally difficult to discern the real Frances Shand Kydd as, like her ill-starred daughter, she sought fervently to portray herself as she believed those she encountered wanted her to be.
Aristocrat and commoner, manipulator and victim, devout Roman Catholic and grandmother of the future king and supreme governor of the Church of England: Frances Shand Kydd was them all.
However, her chameleon-like character meant Mrs Shand Kydd led a life that, like her daughter’s, was marred by sadness and regret.
She was deserted by the man for whom she gave up everything, was vilified as the "bolter" who abandoned her family, and so lost custody of her children.
Then, years after grieving for her first-born son, who died within hours of his birth, she suffered the sudden loss of her youngest daughter, Diana.
More recently, there was the ignominy of a drink-drive conviction, a car crash that she was lucky to survive, and the theft of 100,000 worth of jewellery from her home while she was in London to give evidence at the trial for theft of Diana’s former butler, Paul Burrell.
The final blow was diagnosis of a terminal brain disease - thought to be Parkinson’s, although this was never confirmed - which left her struggling to speak or walk. The timing of the illness was particularly cruel as it came just at the point when she appeared to have found, if not contentment, then a peace of sorts.
As a teenager in 1954, Frances Ruth Burke Roche was a young bride marrying an older man, Edward "Johnnie" Spencer, Viscount Althorp.
She was only 19, but their union in the splendour of Westminster Abbey bore the unofficial title "wedding of the year".
Their first son, John, died when he was barely 11 hours old. The young mistress of Althorp found the pressure to produce a male heir crippling and she was haunted by the premature death of the baby.
A spokesman for the son she eventually had, Earl Charles Spencer - brother of Sarah, Jane and Diana - said yesterday: "We can confirm that Earl Spencer’s mother passed away peacefully after suffering from a long illness. Now this is a private time for the family to grieve."
Buckingham Palace said the Queen had sent a personal message of condolence to Earl Spencer. Prince William and Prince Harry, the latter currently in Africa on a gap year, had been left "deeply upset" by the death of their grandmother, the palace said.
The Spencer marriage ended in divorce in 1969, after she left Althorp to start a new life in Scotland with Peter Shand Kydd, a wallpaper tycoon with whom she had been having an affair. Unusually at the time, Earl Spencer won custody of their children. Diana was only eight and felt her mother’s absence sorely, especially when her father remarried.
Mrs Shand Kydd and her new husband turned their backs on aristocracy, set up home on Seil and opened a gift shop in Oban. But after he left her for a younger woman, she closed the shop and, apart from her charity work, became a virtual recluse.
Mrs Shand Kydd converted to Roman Catholicism ten years ago and once said that she would never place blame or anger over the details of her daughter’s death, as there would be little point. "When Diana died, it was wonderful being a Catholic. I believe that a child is a gift. God can take that gift away without reproach or question," she explained.
Mrs Shand Kydd became a leading figure within the Church in Argyll, and raised more than 50,000 towards the creation of a Catholic house of prayer on the island of Iona. She was especially sympathetic to the errant Bishop of Argyll and the Isles, Roddy Wright, who fled the Church after having an affair with a parishioner.
Diana’s mother was patron of such diverse organisations as the Highlands and Islands Music Dance Festival, the Highland Division of the Search and Rescue Dog Association, and Oban Air Training Corps.
Despite her desire for seclusion, Mrs Shand Kydd seemed to find a purpose in devoting her life to others. She spent time comforting the bereaved families of fishermen, often driving for hours to reach their homes.
She also made some 15 pilgrimages to Lourdes with groups of disabled people. She said of her journeys: "I find it a great privilege to be in their presence. They are an inspiration that helps put life into perspective."
However, it was the death of two of her children that shaped Mrs Shand Kydd and perhaps led those who met her to believe she was a brittle, damaged woman. Indeed, she once described leaving a shop dry-eyed when a woman broke down in front of her, sobbing that she loved and missed Diana. "I’ve cried in public only once since Diana died," she said. "I know it doesn’t matter, but I always felt if I started I might never stop."
On each anniversary of her daughter’s death in 1997, Mrs Shand Kydd made a point of driving alone to the same deserted beach, where she could be assured of no phone calls from newspapers.
It allowed her to remember her daughter the way she chose; she had not spoken to Diana in the four months before her death because of a feud over the princess’s chequered love life.
With all the intrusions on her life since the accident, she once noted: "Sometimes I think the only one resting in peace is Diana."
Too much alike to be best of friends
FRANCES Shand Kydd had a prickly relationship with her youngest daughter, Diana. It was fraught with difficulties, provoked mainly because the two women were so remarkably alike.
They shared the same eyecatching good looks, svelte figure and desire to have their own way - almost at any cost.
Yet, four months before Diana died, she had spurned her mother and refused to speak to her because she had criticised her choice of lovers.
Mrs Shand Kydd had further enraged her daughter, despite her being no slouch at manipulating the media, when she sold her story to Hello! magazine to raise funds for her church. Diana, later described by Mrs Shand Kydd as "tempestuous", returned unopened letters from her mother as the feud deepened in 1997.
Following Diana’s death in Paris, Mrs Shand Kydd made light of the argument she had never been able to settle with her daughter.
But she told biographers that she viewed the rift as temporary. "Of course we argued. Who wants a wishy-washy mum?" she said.
Despite the fall-out, Diana did not remove her mother’s name from her will in a gesture that showed she understood how seriously Mrs Shand Kydd took her role as grandmother to Princes William and Harry.
The mood at the Spencer family’s seat at Althorp, a 13,000-acre estate in Northamptonshire, first grew sullen when Mrs Shand Kydd left her children for another man.
She tried in vain to keep them with her, but was denied by the courts - a decision that weighed heavily with her youngest daughter who was just six years old at the time.
Diana told her biographer, Andrew Morton: "My parents were busy sorting themselves out. I remember my mother crying.
"Daddy never spoke to us about it. We could never ask questions. Too many nannies. The whole thing was very unstable."
The Princess of Wales was said to blame the trauma of her parents’ divorce for all her problems in later life, including her eating disorders. She suffered from anorexia and bulimia. Diana was also said to have tried to take her own life, once when she was pregnant with Prince Harry.
Mrs Shand Kydd’s other two older daughters, Sarah and Jane, were not immune from the family troubles. Lady Sarah McCorquodale suffered from anorexia in her early twenties.
After the princess’s marriage collapsed, her brother, Earl Spencer, rebuffed her request for a country retreat on the family estate, prompting a bitter squabble between the siblings.
Lord Spencer was later accused of cashing in on Diana’s death by burying her at the family estate, Althorp, and charging visitors 10.50 to see the grave.