Ellie's Big Girl Knickers Ellie wants to be just like her mummy but that means she has to give up her nappy and start wearing Big Girl Knickers Will Ellie be able to get to the toilet in time? What happens if she has an accident in her new knickers? Join Ellie as she takes on the almighty toilet and learns to be just like her mum. Ellie's Big Girl Knickers is a great addition to a young child's reading library, as well as a helpful resource to any parent negotiating the amusing and challenging period of toilet training.