Dispirited by the fifth request to re-sketch pepperoni slices on a meat-lovers’ pizza for a home delivery menu, Hess – who’d loved drawing all her life and excelled in art at Lourdes Hill College, Hawthorne, in Brisbane’s east – had reached her limit.

Although she’d had some good jobs since leaving school in 1990 – for Italian Vogue and British Elle – she’d also drawn sex positions for Cosmopolitan magazine and spent months labouring on a 350-page horse-care manual, only for the project to be canned.

Drawing pizza toppings over and over again, however, was the last straw. On that night in early 2008, Hess went to bed heavy-hearted, having quietly decided to give it away and pursue a different career path.

A 3am telephone call changed all that.

“I jumped out of bed and answered the phone, thinking someone must have died,” she recalls. “It was an American woman saying she represented a New York Times best-selling author who had seen one of my illustrations in Italian Vogue and wanted me to do the cover of her next novel.

“She said the author was very well known and I would have to sign a confidentiality agreement. It was the middle of the night … I didn’t know if it was a dream. I thought maybe it was Jackie Collins. I just said yes.”

The next morning, Hess emailed back the confidentiality agreement. It was only then she was informed the work would be for Sex and the City author Candace Bushnell’s next book, One Fifth Avenue.

At the time, Bushnell was at the height of her fame.

Sex and the City the movie, was soon to be released and NBC television series, Lipstick Jungle, based on her novel, was screening.

“My whole spirit was lifted,” Hess says. “I’d finally got a well-paying, exciting job. The horse manual was forgotten.”

Hess, who was living in Melbourne at the time, submitted the cover artwork and Bushnell loved it so much she commissioned her to design a signature look for her previous books, which were due to be re-released. The publisher wanted new designs for every language version – 25 different covers in all.

“At that point, everything changed,” Hess says. “I went to New York when One Fifth Avenue had come out and it was on billboards in Times Square, it was on buses, on top of taxis.”

In a giddy week in New York, Hess was offered work by Tiffany & Co, Chanel, Dior, Vanity Fair and Time magazine.

“It was my dream come true. I said yes to them all,” she recalls.

Taking inspiration from fashion icons such as Audrey Hepburn, Sophia Loren and Grace Kelly, Hess has also worked for high-end clients Valentino, Balenciaga, Cartier, Yves Saint Laurent, Fendi, Montblanc, Laduree, Rolex, Bulgari, Henri Bendel and the Hôtel Ritz Paris.

She created a façade for Tiffany and Co’s Fifth Avenue store in Manhattan and illustrated a book for US first lady Michelle Obama, a “modern-day style guide” titled What Would Michelle Do? Her work has featured on a three-storey exterior wall of Bloomingdale’s in Dubai and on the windows of New York luxury goods department store Bergdorf Goodman.

Hess has an online store with a range of scarves, cushions, stationery, limited-edition prints and last year released her first book, Fashion House with drawings of the home interiors of Coco Chanel, Tom Ford and Elizabeth Taylor, among others.

Her next book, The Dress: 100 Iconic Moments in Fashion, is due in October and Hess says it’s a “celebration of all the dresses that have made my heart sing”.

But for all her achievements, one of her proudest commissions is for this month’s Brisbane’s Mercedes-Benz Fashion Festival.

The 39-year-old mother of two has designed a trio of models in shades of pink as the key promotional image for the festival, now in its eighth year.

“Growing up in Brisbane, aspiring to be a fashion illustrator and watching the RAQ [Retail Association of Queensland] Fashion Design Awards on TV, I never dreamed I would ever go to the [fashion] festival, let alone draw the hero illustration for it,” Hess says.

“I have been incredibly proud to do it.”

Megan Hess grew up in Capalaba and Belmont Heights, in Brisbane’s south-east, the middle child of Bill, a pharmacist, and Jan, who worked in the pharmacy and later curated the Commissariat Store Museum in Brisbane.

Her sister Kerrie, 35, who lives in Brisbane, is also an illustrator, though Hess says they “keep their work pretty separate”.

Kerrie has worked for fashion houses such as Chanel and Louis Vuitton and written and illustrated two books aimed at teenagers – Girl Secrets and Girls Only – and a style book, Shoestring Chic.

Brother Thomas, 40, is a paediatric radiologist at the Royal Children’s and the Mater Children’s hospitals in Brisbane.

In primary school at St Anthony’s, Alexandra Hills, Hess would draw simple caricatures of her classmates and her teacher would comment to her mother that the drawings were basic yet somehow managed to capture the personality of the subject.

“I remember getting a really good reaction to the caricatures and feeling good about them,” she says.

“They were probably terrible, but the kids loved them.”

At 12, she discovered the work of Russian-born French artist Romain de Tirtoff, known as Erte, in a secondhand book store.

“I found a print by Erte and did a bit of research on him and discovered the world of this amazing Russian illustrator … it was when all magazines were illustrated. He was a big star.”

Hess did high-school work experience with a Brisbane fashion designer but soon realised her passion was in drawing the designs, not sewing them.

“Drawing is the only thing I’ve been good at,” she says. “At my school, art was really respected – it was not seen as a bludge or a joke lesson. My art teacher, Mrs [Marita] Artuso, really encouraged me. She told me there were lots of jobs I could do with drawing.”

But Hess was not convinced and after graduating, she enrolled in a Bachelor of Graphic Design at Griffith University.

“Graphic design was never really what I wanted to do but I thought I should do something where I would actually get paid.

“I always had these fears [about art] that I would be in a dark studio painting all day, starving, with 100 cats. Graphic design sounded like something I could make a living from.”

Towards the end of her degree, Hess did a 12-week advertising course and was subsequently offered a plum role as art director with leading Brisbane agency Mojo.

“I was 21 and probably too young,” Hess recalls. “It was an eye-opener to an industry that at that time was filled with flamboyant people, big egos and a lot of money spent on accounts. It was terrifying, but I learnt a lot from it.”

Hess realised advertising was not for her after two-and-a-half years and she moved to London. Her boyfriend, architect Craig Yelland, whom she met at Brisbane’s Mary Street Nightclub when she was 19, followed her.

After six months working in retail, Hess registered with a recruitment agency to try her hand at something creative.

She was sent to a host of jobs, from styling pop stars at Tower Records to window displays for retail chain Laura Ashley. Then came a job as art director of Liberty department store on Regent St.

“I would often book models, makeup artists or photographers,” Hess says. “One day I was asked to find an illustrator to draw the store’s next signature furniture pieces. I offered to do it myself and told them that if they didn’t like it, I’d find someone else.

“So I did and they thought it was great, and they used it in the store’s spring furniture catalogue. At that point, I decided that was what I wanted to do.”

Hess was later contacted by Elle UK to do a full-page fashion illustration.

“When that magazine came out, I think I bought every copy from the newsstand. I was so excited, I can’t even tell you.”

By the time she and Yelland returned to Brisbane to get married in 2001, Hess had enough work to illustrate full-time.

For the past five years, Hess and Yelland have lived in a spectacular four-bedroom apartment in the roof of an 18th century church in Port Melbourne.

Yelland, 40, grew up in Chermside, in Brisbane’s north, and attended Craigslea State High School. He is now a director of Melbourne-based practice Plus Architecture, which recently opened an office in Brisbane.

The couple has two children, Gwyn, 8, and Will, 4. Their home, all white and black and designer-beautiful, seems an incongruous playground for young children.

“Craig and I look at the photos of our home and wish we lived there as well,” Hess laughs. “The truth is that for any photos any magazine has ever taken of our place, they have come in and removed half of our stuff. If only it was so sparse and tidy.”

Hess insists the home is “bulletproof”.

“Because Craig is an architect, it’s really child-friendly,” she says. “The whole place is designed around black and white because if you put black and white together, white never looks dirty.”

That didn’t stop a run-in with a rogue Thomas the Tank Engine toy that landed her in hospital. “Will came into our room and told me he’d had a nightmare, so I let him in our bed to give him a cuddle and calm him down,” Hess says.

“As I was carrying him back to his bedroom, I stood on Thomas the Tank Engine. I fell completely backwards on the floor while still holding my son.

“At first I thought I’d broken my back, it was so painful. In the end, I’d torn two muscles but I was horizontal for four days. I couldn’t move.”

Hess describes her life as “full on”. She does four or five overseas trips a year, with most of her clients based in the US and Europe.

“I try to do any trip in as short an amount of time as possible, just because I’ve got kids,” she says.

“Craig is incredible. It’s very much a team effort. He always looks ten years older when I get back. But he’s amazing. He’s down with everything.”

For all her success, Hess will never forget the night Candace Bushnell saved her.

“I went from struggling to pay the rent to living very comfortably,” she says.

“If I hadn’t got that call, everything could have gone on a completely different path. I’m very grateful to her, and she has become a mentor to me ever since. Drawing is the only thing I’ve been good at and luckily it’s worked out.”