Jackie Collins makes her entrance to the swanky hotel suite where we've arranged to meet, dressed in a trademark tailored jacket, black trousers and plenty of bling, her dark auburn hair blow-dried to within an inch of its life.

The only incongruous accessory is her footwear - comfy white Nike trainers. And she's sporting a bandage on her right ankle.

"I hurt it playing football with the grandchildr en," says the 77-year-old blockbuster novelist, whose books - including The World Is Full Of Married Men, The Stud and The Bitch - have sold in their millions.

"But I love gym shoes," she adds. "I really don't care what people think. I've had my days of Louboutins. But I'll put on some high heels tonight, even with a bandaged ankle, and stagger into a restaurant."

Indeed, Collins, who was made an OBE two years ago, still has incredible energy. On the week we meet, she has a packed schedule of TV and radio appearances, plus a string of print interviews and photo shoots to promote her latest sexy novel, The Santangelos.

The grandmother-of-six has also found time to catch up with her older sister Joan for tea, she mentions. They always meet up when they're in the same city - Joan lives for much of the year in the south of France with her younger husband Percy, while Jackie lives alone in her palatial home in Beverly Hills, next door to Al Pacino.

Over the years, rumours have surfaced that the sisters don't get on, but Jackie says this couldn't be further from the truth and that there's never been any competition between them.

"Joan's five years older than me and was a movie star in Hollywood when I was still at school. Then I went there and later repaid her by giving her the role in The Stud. I wrote the screenplay for free. That made her career soar. And then Alexis Carrington Colby [Joan's Dynasty character] was born."

Collins likes writing about strong female characters - "kick-ass" women - and is particularly enthusiastic about Lucky Santangelo, the strong matriarchal figure in her latest potboiler, the ninth in the Santangelo series.

"Angelina Jolie could be Lucky," she enthuses. "She had the life. She was crazy, into everything and now look at her with six children and everything going for her.

"I like strong women," she continues. "It comes from the fact that I grew up in a rather chauvinistic household. My father [theatrical agent Joseph Collins] was always very chauvinistic and my mother [Elsa] was always very gentle and laid-back. I didn't like the inequality between them. I felt that she should have had more say in what was going on in the home."

All of Collins' 32 books are still in print - she has sold more than 500 million novels in more than 40 countries - and as the world has moved on, so has she, embracing social media wholeheartedly and boasting some 152,000 followers on Twitter, plus thousands of Facebook fans.

She doesn't think much of the competition in sexy female fiction - Fifty Shades clearly leaves her cold and her feisty heroine Lucky Santangelo is the antithesis of Anastasia Steele, the subservient student sex slave to billionaire Christian Grey.

Collins hates the term 'Mummy porn', the so-called genre which has taken off on the back of Fifty Shades to describe erotic fiction aimed at women.

"The term 'Mummy porn' is derogatory. I mean, do they have 'Daddy porn' where guys are hunched over their computer watching porn? No. But women are relegated to 'Mummy porn'. That's disgusting. It really makes it look stupid."

The only good thing to come out of Fifty Shades is the fact that E.L. James has encouraged people into bookstores, she observes.

While stars in Hollywood come and go, some things don't change, Collins reflects, including ageism.

"The film industry is still run by men and a lot of them want to get laid. They just do these movies where they can coerce young girls into being in the movies. The casting couch is still alive and well in Hollywood. For actresses, it's really tough. You've got 35-year-old actresses playing grandmas. It's ridiculous!"

Some of her showbiz tales will be included in her autobiography, Reform School Or Hollywood, due to be published next year ( "It's not going to be a kiss-and-tell but it is going to be interesting..."). Yet behind the glitz and glamour, Collins has had her share of trauma.

"There have been tragedies in my life. My first husband [fashion impresario Wallace Austin, with whom she had a daughter, Tracy] was a drug addict. Wallace was bipolar, but back then, it wasn't diagnosed. They kept on throwing him into psychiatric wards. Then he was put on to speed by a psychiatrist who said, 'Let me show you how to inject yourself', and that was that."

After her first short-lived marriage, she was married for 25 years to her second husband, nightclub owner Oscar Lerman - with whom she had two daughters Tiffany and Rory - until his death from prostate cancer in 1992.

After Lerman died, she fell in love with Italian businessman Frank Calcagnini. They were together for six years and engaged when he died from cancer in 1998.

"I lost my mother to cancer, my husband of 25 years to cancer and then my fiance. I know a lot about looking after people when they are sick. Oscar was a very strong man who was 20 years older than me. I knew he'd had a fantastic life. My kids looked after him so wonderfully and I just kept writing.

"You keep busy and do what you have to do to get through it. With Frank, it was tragic. He was the same age as me and so handsome. He was like a hero from one of my books."

Collins recalls how he'd been diagnosed after having an X-ray due to flu symptoms. Three months later, he was dead.

"He had been so healthy, jogged every day, worked out in the gym, swam. I was completely shocked. We went through a lot in that three months."

She was with him when he died in hospital. Coping has become a part of life.

"I celebrate their lives. I have pictures of my husband, my mother, my fiance all over the house. I keep them alive through photographs.

"I refuse to mourn people, because everybody dies. Death and taxes, you can't avoid either."

These days, she doesn't want another serious relationship. She has three daughters, six teenage grandchildren and all the freedom she needs.

"I like the freedom that I have of doing whatever I want to do, when I want to do it. If I want to buy a car tomorrow, I don't have to consult with somebody about what it's going to be or what colour it's going to be. I can do whatever I want. I live my life like a single man.

"But then I have so many friends too and an amazing family," she adds. "We rent a house in Maui, Hawaii every year. Twelve of us go - my daughters and their kids come along."

Our meeting ends and another picture is taken to tweet to fans. You get the feeling that Jackie Collins will still be 'kicking ass' long after Fifty Shades has turned to grey.

:: The Santangelos by Jackie Collins is published by Simon & Schuster, priced £20. Available now