Robin was born in California and grew up in an Oxford college, across the road from the house where Alice in Wonderland lived. She has been making up stories all her life.

When she was twelve, her father handed her a copy of The Murder of Roger Ackroyd and she realised that she wanted to be either Hercule Poirot or Agatha Christie when she grew up. She spent her teenage years at Cheltenham Ladies' College, reading a lot of murder mysteries and hoping that she'd get the chance to do some detecting herself (she didn't). She went to university, where she studied crime fiction, and then she worked at a children's publisher.

Robin is now a full-time author, and her books are both award-winning and bestselling. She lives in Oxford.