The Very Big Secret — Enid Blyton

Granny has come to look after Sam and Rosie because Mum has had to go away for a few days' rest. She promises to bring them back a wonderful present. Sam and Rosie decide to go down to the meadows and search for honeysuckle. Sam takes his bike and Rosie takes her toy pram. But when they get back, there is a real live baby in the pram. How on earth did it happen? And what will they do? A new series of Blyton books, written during her lifetime and now updated.