I know how lucky I am,” she says.Ben and Zac Goldsmith, sons of the billionaire philanthropist and businessman Sir James, have thrown their not inconsiderable wealth behind environmental campaigns.Ben helped to unite two wealthy dynasties last year when he married Kate Rothschild in Bury St Edmunds (between them they are worth around £300m). Richard Branson’s daughter Holly, despite being worth about £50m, is now studying medicine at University College in London and living happily with friends in nothing seedier than a hall of residence.Ivanka Trump, daughter of “The Donald” and the equally larger-than-life Ivana, is a business student who does jobs in the holidays despite her £52m fortune “I’ve never been big into self-pity. And how it must differ from the tales of woe that circulate at the Priory in Surrey, where their less fortunate cousins rub their noses and sniffle into the hot water and lemon.But some of them are doing something right. “It’s the cause of all the problems.”Of course, it’s not obligatory for a young heiress to end up tear-streaked and dribbling, toasting the disappearance of another husband with sleeping pills and flat champagne.One wonders what kind of advice must be flying around at Annabel’s nightclub in Berkeley Square where the young rich rub shoulders.

Last January, Allegra’s near-contemporary Athina Roussell inherited assets from her grandfather Aristotle Onassis estimated to be worth £1.5bn. Allegra must hope not to follow her mother, Christina Onassis, who married a succession of 24-carat bounders before dying of heart failure when Athina was just three, her death thought to have resulted from a slimming pills overdose “I want to forget the name Onassis,” Athina once said. Allegra keeps herself and her hobbies hidden from the press as much as possible and is always shadowed by a team of bodyguards.The traditional role of poor little rich girl is not one many mothers would wish for their children. When the will was read, revealing her huge inheritance, she asked, aghast, “Why did Uncle Gianni choose me?”Donatella made sure both her children talked to child psychologists after learning of their uncle’s death in a TV newsflash between cartoons, but they will never have an ordinary life. “Because Allegra tells me the truth about Donatella.” When he died she felt guilt, telling her mother that uncle would have been all right if only his favourite little girl had been with him. If she doesn’t, it’s back to the family firm.Allegra was two days old when she attended her first Versace show She has mostly avoided the cameras ever since. Described as “serious, sensible and bright”, with her hair in pigtails and her nose in a history book, the teenager was devoted to Gianni “I like to talk to Allegra,” he said.

Mum has given her until the age of 25 to succeed as an actress. While Allegra is beginning to look almost as startling as her mother, Donatella, she is also a bookish teenager who likes to wear jeans, trainers and comfortable old cardies and wants to study acting after she finishes an English and drama degree at New York University. The inheritance is also tainted by sadness: it is the result of the death of her beloved uncle, shot seven years ago outside his Miami mansion. Allegra’s stake could be worth more than £130m if she sold it on, though this is unthinkable, at least for now, however uneasy she might be about her new life.Allegra will tomorrow attend her first shareholders’ meeting at the troubled company, which has falling sales and a pre-tax loss that has doubled to £13.4m. The skinny, kohl-streaked face of Allegra Versace Beck staring out from the papers on her 18th birthday last week provoked conflicting emotions: should we feel envy or overwhelming pity for the girl uncle Gianni Versace called his “little princess”? We all dream of wealth, but for Allegra – and many others in the same privileged position – it seems more of a nightmare.
Her birthday present was a 50 per cent stake in the Versace fashion empire, whose sales totalled £268m last year.