It's tough being an heiress. Public opinion and reality TV are against you, altruistic endeavours are greeted with snorts of derision and your spending habits are broadcast the minute you reach for your credit card.
When you are the daughters of the Formula One mogul, Bernie Ecclestone, you do not even need to look for fame to add to your already considerable fortunes to find yourself in the spotlight.
What daughter of marriageable age would not appreciate a bit of help from her dad with buying a new home? It is just that the pile Bernie has just bought Petra, 22 (sister to Tamara, 26) is, at £92m, the most expensive house in America, and comes with its own bowling alley and citrus orchard. She already has two houses in Chelsea, the biggest of which is worth £56m. And what mother would not be proud to see her daughter following in her own footsteps career-wise? It is just that Tamara is the new face (and body) of Ultimo swimwear.
The two gangly society beauties take after their mother Slavica Radic, a former Armani model, rather than their diminutive father, whose reported personal fortune of £1.5bn more than makes up for what he lacks in stature. But despite their looks and good fortune, the sisters are known for having their heads screwed on.
"The most important thing Dad has taught us is that money isn't everything," Tamara said in an interview in 2005. "Of course, it makes things easier, but it can bring its own problems. You don't find happiness by being able to buy everything you want, whenever you want it."
This from the girl who bought a £9,000 Rolex with her first pay cheque. Still, the sisters appear to prioritise their personal lives ahead of their bank balances and, perhaps because of the pressures they feel as two of the world's richest young women, have chosen to settle down early. Petra is engaged to her businessman boyfriend, James Stunt, 27, while Tamara is dating a stockbroker, Omar Khyami, 37.
The sisters have said their parents provided a grounding influence. "They both came from humble beginnings," Petra has said, "so they respect money enough not to waste it. Mum does all the shopping herself in Waitrose and often looks for two-for-the-price-of-one deals."
It is quite a contrast to some of the more lavish spending of the Ecclestone sisters. They travel regularly on their father's private jets and, as teenagers, shared a credit card, on which they admitted to having an allowance of several hundred pounds a month. Petra held an engagement party last month with a million-pound Bugatti supercar as a centrepiece and a £250,000 private performance by Rihanna. "It was incredible," said one guest, "but Tamara's speech really stripped away all of the glamour – it was very sweet. She had tears in her eyes."
Slavica Ecclestone takes her daughters back to her native Croatia three times a year with the express intention of reminding them how ordinary people live. During the 23 years she was married to their father (the couple separated in 2009), she insisted on doing the ironing herself.
"We never had nannies or housekeepers," Tamara told The Times earlier this year. "Mum was into cooking and cleaning and doing everything. She was inspirational."
The Ecclestones were raised in West London and went to the Kensington Prep School in Fulham and then Frances Holland School for Girls in Belgravia. When she was 18, Tamara worked as an assistant on her father's racing magazine for a starting salary of £15,000, before going on to work as a presenter for Sky Sports Italy. She is hoping to star in an Osbournes-style reality TV show this year. "I hope I will be taken more seriously," she said in January, "perhaps [as] a businesswoman rather than a socialite or whatever they call me."
Petra, meanwhile, turned down a place at Central Saint Martins to be an apprentice on Savile Row and, in 2009, started up a luxury menswear label, 'Form'. It was launched at the Monaco Grand Prix and, after two collections, closed thanks to the unfriendly financial climate for fledgling high-end goods companies. She is not deterred, this week launching a range of bracelets she has designed for a meningitis charity (Petra contracted the disease in her teens).
Tamara, meanwhile, has bought a disused pub in Knightsbridge and intends to refurbish and reopen it. Both want to earn their own crust – during her time as designer, Petra was said to be in the office from 8.30am until 6pm every day.
If one of the great hurdles for heiresses is to be taken seriously, it does not help when so many of them are pictured falling out of nightclubs. Not so the Ecclestone sisters: Petra does not drink or like partying, while Tamara – having been burnt by a kiss-and-tell boyfriend at the age of 16 – is equally discreet with her private life.
Resilience is part and parcel of the Ecclestone's lives, from their father's donations scandal to the false accusation that their mother used to be a Communist spy. Then there is the assumption they are feckless rich girls with so much money to burn that any initiative of theirs can easily flop without financial consequences, as well as the worry that anyone in their coterie of friends and admirers might only be looking to gain a little stardust by association.
"They do basically have to deal with a lot of hangers-on," says a friend of the sisters, "but they each have quite a small group of close friends that they have known for a long time. A lot of people try and use them, but their friends are very loyal. One of Petra's bridesmaids is a friend from primary school."
"Naturally, I'm wary and of course it crosses our minds that people might want us for our money," Tamara has told the press. "How can anyone ever be 100 per cent sure? Those people that expect you to pay the bill because you're rich aren't true friends and we stay clear of them. I don't need anyone to look after me financially and, while it's hard to trust that a man loves you for the right reasons, you have to take a leap of faith. I think I'm a good judge of character."