'Are your twins normal?' Mrs Pullein-Thompson was asked. 'Good God, I hope not, ' she retorted. The twins were Diana and Christine who, with their elder sister, Josephine, wrote more than 150 books, which have sold in their millions around the world. Fifty years after the joint publication of their first book, It Began with Picotee, the siblings wrote about their extraordinary childhood with lovable, but often unreliable animals and unforgettable...