The Duchess of York is set to make her first official Royal appearance for 14 years when she attends the Order of the Garter service at Windsor in a fortnight. Fergie will also attend the private family tea that will be held after the ceremony.

But the biggest sign of her rehabilitation into the Royal fold will come when she co-hosts daughter Princess Beatrice’s 18th birthday party at Windsor Castle on July 15.

For Beatrice this is more important than the event itself. It’s the best gift the Queen could have given her. The Monarch is using the occasion to mark the return of her former daughter-in-law, the often-exasperating Sarah Ferguson, back into Royal favour. Why, we may ask?

The UK Mail On Sunday reports: “On the face of it, the rapprochement is an astonishing about-turn for the Palace, which has steadfastly refused to acknowledge Fergie, mainly at the behest of Prince Philip who hasn’t uttered a single word to her in ten years. In truth, it is the culmination of many years of behind-the-scenes lobbying by Beatrice to have her beloved mother once again in favour.”

Princess Beatrice was born at 8.18pm on August 8 (8/8), 1988 — the most auspicious date of the past century, according to the Chinese calendar. She is, by many accounts, a genuinely helpful, good-natured girl. Her election as Head Girl of her Ascot School demonstrated how popular she is with her peers, despite a long battle with dyslexia.

The party promises to be the most lavish since Prince William’s 21st birthday celebrations three years ago. This time, the dress code will be 18th century, reflecting the many “8s” associated with her birth.

The Queen rarely gives parties on such a grand scale and the fact that she has done so for Beatrice is a sign of her affection for the young granddaughter who calls her “Granny One”.

The Queen has also instructed 16 senior Buckingham Palace aides to help the young Princess adjust to public life. No expense is spared for Bea, who is 5th in line for the Throne.

The centrepiece of the bash will be a splendid Georgian banquet prepared by the Queen’s own chefs. The music will be supplied by a string quartet, while the historic Waterloo Chamber will be filled with the scent of English roses.

Prince William and Prince Harry, together with the Duke of Edinburgh, will be among the 400 guests who will transform themselves for the night into 18th-century characters from Mozart to Marie Antoinette. It’s widely agreed that Beatrice’s birthday party is set to be the social event of the summer.