She once told how her biggest worry in life was running out of money.

However, Dame Jilly Cooper – who passed away unexpectedly this week following a fall – is believed to have left a remarkable £10 million estate, the Daily Mail reports.

Renowned as the queen of the ‘bonkbuster’, she sold over 11 million books in the UK alone, solidifying her status as one of Britain’s most beloved female authors.

Dame Jilly’s hugely popular novels, which detailed the intriguing lives and misdemeanors of the horse-loving elite, garnered her more than £5 million.

Her appeal found a new audience when Rivals – one of her top-selling novels – was adapted into a hit series on Disney+, bringing in an additional £2 million for her.

Moreover, her financial portfolio benefited from savvy real estate investments, notably the 14th-century residence she purchased in the Cotswolds for £145,000 in the 1980s, now valued at £3 million.

While writing Riders, the inaugural book of her 11-part Rutshire Chronicles, Dame Jilly faced the potential loss of her home, which she managed to avert, setting the stage for her subsequent success.

She once said: ‘We were always broke and worried about money. But then Riders got published.

Dame Jilly’s best-selling romps portraying the scandals, betrayals and fabulous lifestyles of the horse-loving country set earned her in excess of £5million

Jilly Cooper with her daughter Emily Tarrant (left) and son Felix Cooper (right) and his wife, when the acclaimed author received a Damehood at Windsor Castle last year

‘Obviously, the bank manager had been sent a copy and so he came down for the weekend.

‘He sat on our terrace and said, “Lovely old property this. What a tragedy you have got to sell it and don’t think your dirty little book will get you out of it”.’

The book, published in 1985, went straight to number one in the bestseller lists.

It became the first of Dame Jilly’s novels to be adapted for TV with a combined audience of 24 million viewers turning in for the two-part ITV mini-series – and launched her on the road to fame and fortune.

But, haunted by the memory of nearly losing her home, she told The Sunday Times in 2020 that her ‘only real worry’ had always been money.

She said: So I know it sounds silly, but I worry about it running out.’

In 1994, Dame Jilly was reportedly one of Britain’s highest-earning women after being paid more than £630,000 over 12 months in royalties and TV rights.

One analyst told the Daily Mail: ‘Her brand of “bonkbuster” novels meant that from early in her writing career she commanded big advances with publishers knowing sales were sure to follow.

’In the 80s she stepped into another league with the publication of Riders.

‘It was the first in the Rutshire Chronicles series of books which put Jilly’s work into households across the UK and around the English-speaking world.

‘From that point on her books commanded six figure up-front payments and have been earning her and publisher Penguin Random House millions in sales since.

‘Numerous editions of the books have been published and there was even a 40th anniversary edition of Riders published earlier this year.

Dame Jilly Cooper – who died unexpectedly this week after a fall – is estimated to have left behind a staggering £10million fortune

Jilly Cooper pictured with her daughter Emily in 2012

Her manor house in Bisley, Gloucestershire, which she and her family moved into in 1982

‘The series which also included novels Rivals and Polo is believed to have earned her in excess of £5 million.’

Dame Jilly, whose father was a brigadier, earned just £6-a-week from her first writing job – as a junior reporter on the Middlesex Independent.

She moved into public relations and as a copywriter but was sacked from 22 jobs before finally working in publishing.

In 1961 she married Leo Cooper who was a publisher of military books.

Unable to have children of their own, they adopted son Felix, 57, and daughter Emily, 54, who are now set to inherit their mother’s fortune.

When the children were adopted they lived with their parents in a turn-of-the-century working man’s cottage in Fulham which Dame Jilly bought for £7,000 in 1968.

In 1982, the family moved to their manor house home in Bisley, Gloucestershire – which is set in 14 acres of fields and water meadows in a Cotswolds location that would provide the inspiration for Dame Jilly’s raunchy novels.

The third book in her series Polo was published in 1991 and went on to become the biggest selling hardback novel of the year.

Dame Jilly has told how, after a lunchtime drinking session with Felix, she splashed out £100,000 buying a house in Fulham after receiving a ‘staggering’ royalty cheque from the book.

She went on later to describe the impulse buy as the ‘best financial move’ she had ever made.

At the time, Dame Jilly’s marriage was going through a rocky spell after publisher Sarah Johnson publicly revealed in 1990 that she had been having a six-year affair with Leo.

The couple reconciled and Dame Jilly continued her writing to fund their lifestyle and later Leo’s care after he was diagnosed with Parkinson’s disease in 2001.

And she didn’t stop after Leo died aged 79 in 2013. Dame Jilly wrote or helped to compile more than 40 books including 18 novels which she crafted on an old typewriter named Monica.

Dame Jilly was awarded her damehood in 2024 for services to literature and charity

Jilly Cooper and her husband Leo. He died in 2013 aged 79

The most recent, Tackle!, was published in 2023.

The novelist – who was awarded her damehood in 2024 for services to literature and charity – said at the time: ‘I’m 86 now and have forgotten how to do it!

‘It’s quite difficult to write sex scenes, you can’t go on finding ways to do it differently.’

Meanwhile her worldwide fame was given a huge boost after Disney commissioned the star-studded TV production of Rivals starring former Dr Who actor David Tennant, Poldark star Aidan Turner, Danny Dyer and Emily Atack.

Dame Jilly died after a second extended season of the drama had begun production.

In a statement, Felix and Emily said: ‘Mum was the shining light in all of our lives. Her love for all of her family and friends knew no bounds. Her unexpected death has come as a complete shock.

‘We are so proud of everything she achieved in her life and can’t begin to imagine life without her infectious smile and laughter all around us.’

Felix and wife Edwina, 58, are parents to daughters Scarlett and Sienna, and run their own TV production company.

They live in a £750,000 four-bedroom detached property just a two minutes walk from the family manor house.

Emily and husband Adam – who are parents to sons Jago, Lysander and Acer – own a £1million property in a market town 20 miles away.

Emily, a professional TV make up artist who worked with stars including actress Jane Seymour, and Dawn French and Jennifer Saunders, now creates wedding day make-up and offers expert lessons for brides-to-be.

Queen Camilla was among those who paid tribute following Dame Jilly’s death on Sunday.

In a touching message, she remembered a woman whom she described as a ‘wonderfully witty and compassionate friend’ saying: ‘Very few writers get to be a legend in their own lifetime, but Jilly was one, creating a whole new genre of literature and making it her own through a career that spanned over five decades.’

She added: ‘I join my husband, The King in sending our thoughts and sympathies to all her family.

‘And may her hereafter be filled with impossibly handsome men and devoted dogs.’

The pair first met when Queen Camilla was married to Andrew Parker Bowles who is said to have been one of the inspirations for rakish aristocrat Rupert Campbell-Black – the central character in the chronicles.

Incredibly, the novel which launched Dame Jilly’s glittering career nearly never made it to the bookshops.

She wrote the first draft of Rivals in 1970 but lost the only copy of the manuscript after leaving it on a London bus.