(CNN) Judith Krantz, whose best-selling romance novels told racy tales of the rich, died of natural causes Saturday, her publicist said. She was 91.

Krantz is known for her novels "Mistral's Daughter" (1983), "I'll Take Manhattan" (1986), "Scruples" (1978) and "Princess Daisy" (1980). She's sold more than 80 million copies of her novels, and they've been translated into over 50 languages, her publicist said. She wrote her first book at age 50, launching her into the romance novelist stratosphere.

Krantz, originally from New York, became wealthy from the sale of her books. In a letter to readers in her 2001 autobiography, "Sex and Shopping: The Confessions of a Nice Jewish Girl," she said she had a different life from the majority of women of her generation and background.

"While I seemed like another 'nice Jewish girl,' underneath that convenient cover I'd traveled my own, inner-directed path and had many a spicy and secret adventure," she wrote. "I grew up in a complicated tangle of privilege, family problems, and tormented teenaged sexuality."

Krantz was the oldest of three children, and the "daughter of worldly and cultivated parents" as she writes in her autobiography. Though her interest in clothes began when she was a child, she said she was unpopular growing up, having very few friends until she reached high school. She wrote that those years had been "burned into her psyche."

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