 During the Second World War, Lady Allen, with the support of the Home Secretary, Herbert Morrison, with whom she was friends, established a scheme whereby waste material from the bomb sites were turned into children's toys.After World War II she served as a liaison officer with UNICEF in Europe and the Middle East.She campaigned for facilities for children growing up in the new high-rise developments in Britain's cities and wrote a series of illustrated books on the subject of playgrounds, and at least one book on adventure playgrounds, spaces for free creativity by children, which helped the idea spread worldwide.