NEW YORK —
Her sister, Sophie Severs, confirmed the death without specifying a cause.
“Angus, Thongs and Full-Frontal Snogging,” published in 1999, was written in the form of a diary of a British teenager, named Georgia Nicolson, who is annoyed by her parents and wrestles to find her place in the world.
“It was a true-to-life hilarious retelling of my life at 15,” Ms. Rennison wrote in an exuberant first-person essay in The Guardian in 2014.
She would go on to write 10 books in the series, “The Confessions of Georgia Nicolson,” which were popular with young readers in Britain and around the world.
As Ms. Rennison described it, she was a bit of an accidental novelist, becoming one in midlife. Already known in Britain for a one-woman show she had written and performed, she received a phone call one day from a publisher who had read an article she had written for a newspaper about dating after the age of 35.
As she recounted the call on her website: “They said, ‘We loved your article, it was so funny, would you like to write a book?’ And I thought, ‘Ooh, how sophisticated!’ And she said, ‘No, no, no, we’d like you to write a teenage girl’s diary.’
“And I said, ‘Oh, I’m quite flattered, but why me?’ And she said, ‘Well, we read your article and we thought that it was so self-obsessed and so childish that you could really do a good job.’”
The US edition of “Angus, Thongs and Full-Frontal Snogging” included a glossary. “Snogging,” for example, meant kissing; “joggerbums” were jogging pants; and “nuddy-pants” was not wearing anything at all.
“They don’t really get our language,” Ms. Rennison said of Americans in The Guardian.
The book was adapted into a film by Gurinder Chadha, the director of “Bend It Like Beckham,” in 2008.
Many of the books in the Georgia Nicolson series made The New York Times bestseller list for children, including “Knocked Out By My Nunga-Nungas,” “On the Bright Side, I’m Now the Girlfriend of a Sex God,” “Away Laughing on a Fast Camel,” and “Dancing in My Nuddy-Pants,” which made it to the top of the list of children’s chapter books in 2003. The series as a whole was included in the bestseller list in 2005 and 2008.
Besides her sister, she leaves her daughter, her mother, and a grandson.