It would probably have delighted Diana, Princess of Wales, that nearly ten years after her untimely death she is still generating headlines. It is less amusing for her sister, Lady Sarah McCorquodale, who is attracting attention over the guest list for next week’s memorial service, and what role she will play in it.

Lady Sarah, 52, was often described as unofficial lady-in-waiting to her sister, and was the sibling the Princess turned to during the breakdown of her marriage. “On difficult days,” one friend said, “Sarah kept everyone buoyed up and was great fun to be with.” This could be, as one friend put it tartly, because life in Lincolnshire – where she lives with Neil, her landowner husband, and their three children – can be less than scintillating. Be that as it may, Lady Sarah was the natural choice to head to the fund established in the Princess’s memory.

Problems arose almost immediately: there was the deal that saw the Princess’s signature scrawled on tubs of Flora margarine; the scratchcards; the decision to sue The Franklin Mint that cost £4 million and failed and, last weekend, questions were asked as to why the fund was proposing to spend £10 million promoting the rights of asylum-seekers.

Lady Sarah, who got six O levels, is said to be the clever one of the family. But she shared with her younger sister a less-than-glorious school record: while the Princess was winning praise for her immaculately-groomed hamster, Lady Sarah was expelled for bad behaviour. Like her sister, she suffered from an eating disorder and dated the Prince of Wales, a relationship that is said to have ended when she told a magazine that she wouldn’t marry anyone she didn’t love “whether he was the dustman or the King of England”. The experience taught her discretion, and she has told friends repeatedly: “I will never talk about Diana.”

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Yet though undoubtedly well-meaning, her tenure as president of the fund has been described as misguided. Matters are hardly helped by her role on the committee that backed the blighted Diana Memorial Fountain in Hyde Park.

Then there was Paul Burrell, the former butler. Initially friendly towards him – as an executor of her sister’s will, she arranged for him to get £50,000 – relations soured after he was deemed to have become too much of a celebrity. His role as fundraising manager was axed with the startling words: “Remember where you are from.” Burrell dubbed her McCrocodile and claimed that she had been jealous of the Princess.

The Fund is limping along, but interest in the Princess will eventually, presumably, wane. However, as one friend remarked, it is only since her sister’s death that Lady Sarah’s life has had any purpose outside of her family.

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