My mum's going to explode

'Oooh! I'm going to be a granny!' she cried. 'You already are a granny, Granny.' I pointed out. '. . . Oh yes. So I am!'Nicholas's mum is having a baby. It's going to mean some big changes. His mum's getting ENORMOUS and Granny wants to live in the garden! But that's not all, because there's an even bigger shock to come . . .