04/24/2013 at 03:00 PM EDT
Before she was a lifestyle guru and media mogul, Martha Stewart
was comfortable on a catwalk – sort of.
Stewart, who now espouses confidence in her daily life as she juggles all her businesses, tells Parade
in a new interview that she wasn't always as steady on her feet – especially as a 13-year-old model.
"I knew I was good enough to get $60 an hour, which was the going rate at the time," Stewart, 71, tells Parade
, adding that she started modeling "just for money." "I wasn't the cover girl. I wasn't Suzy Parker. But I should've been."
"Maybe if I had had somebody encouraging me," she says. "But then I got married when I was 19."
admits that her early modeling gig "was fun."
In her new book, Living the Good Long Life: A Practical Guide to Caring for Yourself and Others
, Stewart is reflecting on her life. "When you're through changing, you're through," she tells Parade
She also reflects on her stock sale, which resulted in her imprisonment
("I don't consider that a mistake," says Stewart. "It was a normal thing that people do every day.") and her admiration for Hillary Clinton ("She did a phenomenal job as secretary of state.").
But mostly, Stewart is looking closely at her life
– and even prepping a new autobiography.
"I have my title and everything," she says of her plans to some day write that book. "I've led such an interesting and complicated life that it's getting to be time to record it."