Kathy Lette has written several bestselling novels, including Foetal Attraction and Mad Cows. Her latest book, To Love, Honour and Betray, was published in paperback by Black Swan this month.

Born in Sydney, Lette achieved notoriety as a teenager as co-author of Puberty Blues, an autobiographical novel that was made into a film in 1981. She has worked as a newspaper columnist in New York and a sitcom writer for Columbia Pictures in Los Angeles. Lette, 50, lives in West Hampstead, London, with her second husband, Geoffrey Robertson QC, a human rights lawyer, and their children, Jules, 18, and Georgie, 16.

How much money do you have in your wallet?

Whatever the kids haven’t “borrowed”, so usually about £50. If only I’d stood over their cots whispering “paper round”.

What credit cards do you use?

Only my NatWest debit card. When rich, famous women talk about their plastic surgery, I always think I’ve had plastic surgery, too — cutting up my credit cards.

Are you a saver or a spender?

If I have money, I tend to spend it. A budget is a just a schedule for going into debt, systematically. My only real economy drive has been to give up taxis and take up walking, saving me about £40 a week. And people think the only thing an author runs up are bills.

Do you take an interest in your finances?

Isas, Sipps and Peps all sound like some kind of disease. It’s probably time I learnt about them, though. To Love, Honour and Betray was inspired by a statistic that claimed 59% of married women would leave their husbands if they felt more financially secure. It seems women remain in wedlock — which is a little more like padlock — because they don’t know which of the three remotes works the video, or how to balance a chequebook. My book inspires women to stand on their own two stilettos and not be intimidated by the jargon of male bankers.

How much did you earn last year?

You’d have to ask my agent, because all I know is that it’s a six-figure sum. To make proper money, you must get an agent, even though they take a massive cut. But as all writers know, unless you make it on to Richard and Judy’s reading list, the only really lucrative form of writing is ransom notes.

Have you ever been really hard-up?

A writer’s life is a bit like a rollercoaster. Some books sell, while others flounder. I have been financially independent since I left home at 15. Consequently, I have often been very broke.

When I was 16, I was in a punk band and lived in an inner city squat. My only food source was the stale cakes thrown out by the local shop. I was poor, but porky.

Do you own a property?

I have a five-bedroom house in West Hampstead, which we bought in 1996 for £500,000. I’ve no idea what it’s worth now as it’s not for sale.

What was your first job?

When I was a teenager, I worked as a bedpan emptier at Sutherland public hospital, near Sydney. I earned about A$4 (£2) an hour, but it’s clearly where I honed my toilet humour. I’ve had to scrape the bottom of the job barrel — from bath plug maker to kissogram girl, jillaroo (Australian cowgirl), buxom wench, encyclopaedia seller, masseuse and human street sign.

What is the most lucrative work you have ever done?

Writing sitcoms for Columbia Pictures in 1988. All those shows we love — like Seinfeld, Frasier and Friends — are written by about 10 people. They lock you in a windowless room, which I used to call the gag gulag, and force you to make jokes all day. It’s like being a stand-up comedian, except sitting down. I had no life, but earned about $5,000 (£3,000) a week.

Are you better off than your parents?

I am now, probably. My parents worked for the government. My dad was an engineer and my mum a teacher. They were frugal and saved their pennies, but last year were ripped off by a financial adviser. They lost their life savings — about A$1m. To err is human, but really to screw things up requires a financial adviser.

Do you invest in shares?

No. As a feisty feminist, my fantasy is that I’m strutting round the city with a couple of venture capital portfolios tucked up each sleeve, but in reality I’m innumerate. Put it this way — I think stagflation refers to something the upper classes stalk at Balmoral.

What’s better — property or pension?

My property is my pension. A pension is the art of spending money without getting any fun out of it. My girlfriends and I have decided that where there’s a will our children really don’t have to be in it. We don’t want to end up in a maximum-security old people’s home where we sit round knitting. So we’ve decided to pool our resources, buy a boat and go cruising on the Med.

Do you manage your own financial affairs?

I have an accountant who visits once a month. He does the books of lots of writers, so is used to chaos. And I have another to do my tax returns, but I do keep half an eye on him. I learnt the hard way not to absolve all responsibility. My agent sold the film rights to my first novel, Puberty Blues, for a measly A$500. The movie went on to become the biggest box office sensation in Australian history. Unfortunately, my agent had the brain frequency of a house plant. There was no escalation clause in the contract so I made no money. Years later, I made about A$300,000 by selling the rights to another novel, Altar Ego, to Scott Rudin, the producer. The film was never made, but it did make me feel slightly better about the money I lost on Puberty Blues.

What is the most extravagant thing you have ever bought?

A two-bedroom apartment in Sydney overlooking the harbour. It was on the market for A$1.7m but I got it for A$1.3m.

What is your money weakness?

It’s got to be shoes. When you put your foot in your mouth as often as I do, you simply must be well-shod. And champagne — it’s nature’s penicillin.

What aspect of the tax system would you change?

I would adopt the Irish system in which artists don’t pay tax.

What is your financial priority?

My biggest fear is leaving my kids stranded. I always pooh-poohed insurance, but after I had kids I took out a life insurance policy with Skandia. It has grown quite big, so my husband should be bumping me off any day now.

What’s the most important money lesson you’ve learnt?

I have women pals whose husbands’ wedding vows turned out to be: “Till death do us part — or till someone younger comes along.” My advice is to love your husband, but get as much as you can in your own name.