The real life of the world's most famous "Shopaholic"

In "Confessions of a Shopaholic," Isla Fisher plays Becky Bloomwood, a young journalist head over heels with shopping, and way over her head in debt.

She is a character straight out Sophie Kinsella's world; the author who brought her to life.

Monday night in New York, fans of the best-selling novelist flocked to put her newest book, "Shopaholic to the Stars," on their shopping list, reports CBS News correspondent Charlie D'Agata.

"A light went off and I thought, 'hang on a minute! Why has no one done this?'" Kinsella said.

Her instinct was right on the money.

The bestselling author has written 22 novels -- published in 39 languages and 42 countries -- selling tens of millions of books worldwide.

She tapped into the one thing that can make a woman go weak at the knees: shopping.

"It's a feeling, it's a lust!" she said.

Getting swept up in that lust is a lot of what Kinsella's stories are about, and something "Becky" shared at a meeting of reformed shopaholics in the film.

In the new novel, Becky lands a Hollywood dream job: celebrity stylist paid to shop with other people's money -- a job Kinsella said she would savor herself.

"When I come to a new book I'm like, 'hi Becky, let's have some fun together,'" she said. "And I step into her shoes and look at the world through her eyes and off we go."

In real life, she's author Madeline Wickham. Sophie Kinsella is just a pen-name she used for her shopaholic series.

She invited CBS News to her London townhouse for a rare glimpse of the home she shares with husband Henry. And Kinsella, who writes in the first person, admits there are sometimes blurred lines between her fictional and family life.

"The only disadvantage is that I am sometimes away with the fairies when I should be focused on them," she said.

She has five children and somehow still finds time to do it all.

"Well, I've done it over a long span of time, so, I have children ranging from 18 down to 2," she said. "I have every size in stock."

She has her share of critics, too, who have dismissed her books as "chick-lit," especially given her privileged background and her education; she studied economics at Oxford University.

"You're sitting alone in your room and you're tapping away and you hope people enjoy your book and then off it goes," she explained. "But then you get somebody who says, 'well, you know what? I've read your book in the middle of the night when I was recovering from operation and it got me through.' I mean how can you do anything better in life than that?"