Cecelia Ahern has already conquered the adult fiction market - next up is teen novels.
The 33-year-old's first book for teenagers, called Flawed, will be published next year, under a new publishing deal.
HarperCollins Children's Books has acquired the UK and Commonwealth rights to her two teen novels.
"Cecelia has a unique gift for creating stories that hook the reader in, and Flawed grabs from the first page," said Nick Lake, publishing director.
The novel is set in a world where perfection is valued above humanity. The heroine of the novel, Celestine, finds herself excluded from the system after an act of kindness to one of the flawed people.
The book is due to hit the shelves in the summer of 2015.
Meanwhile, the second book called Perfect will follow in 2016.
It has been a busy time for the mum of two. Her latest novel, The Year I Met You, tells the story of a workaholic woman who loses her job and becomes obsessed with her troubled male neighbour, who is also going through a hard time.
And earlier this week, Cecelia was centre stage at the glitzy London premiere of the much-anticipated movie Love, Rosie.
The film, based on Cecelia's 2004 novel Where Rainbows End, stars Lily Collins, Sam Claflin and Suki Waterhouse.
She said that she never writes a book with the hope it will be turned into a movie.
"No, never. If I wrote it from the wrong perspective it would be a lesser quality book - it would be contrived and dishonest. You have to write it from a good place. It's exciting when books are made into movies but it's not my intention," the author said.
Cecelia has sold 16m books worldwide, since she first got a €1m book deal for PS I Love You at the tender age of just 21.