She created an innovative body of work that combined realistic, contemporary children in real-world settings with magical objects - what would now be classed as contemporary fantasy - and adventures and sometimes travel to fantastic worlds. In doing so, she was a direct or indirect influence on many subsequent writers, including P. L. Travers (author of Mary Poppins), Edward Eager, Diana Wynne Jones and J. K. Rowling. C. S. Lewis wrote of her influence on his Narnia series and mentions the Bastable children in The Magician's Nephew. Michael Moorcock would go on to write a series of steampunk novels with an adult Oswald Bastable (of The Treasure Seekers) as the lead character. Most recently, Jacqueline Wilson has written a sequel to the Psammead trilogy, entitled Four Children and It.