Both children attended Stoatley Rough School in Haslemere, Surrey. Her pre-mortem legacy includes letters written by the children to their father in London and to their mother and grandmother in Brussels during this time. The letters describe the girls’ school and everyday life in England. A visit to London by her father Josef Cassel is the subject of her unpublished manuscript “A London Diary”. The young author describes her experiences in the metropolis on 23 handwritten, richly illustrated pages. In 1940, the family together reached the USA, where Lili studied art at institutions including Washington Irving High School and the Art Students League in New York and worked as an illustrator. One of her posts included that of book jacket designer for the World Publishing Company. The first book to contain her illustrations, the children’s book “The Rainbow Mother Goose” (Cleveland: World Publishing Company, 1947) was acclaimed by the American Institute of Graphic Arts as one of the "Fifty Best Books of the Year". Besides working as an illustrator, she also taught calligraphy, for example at the New School for Social Research and at Johns University in Queens, NY. In 1952, she married Erich Wronker, who had emigrated from Frankfurt am Main with his family and whose family had previously own the Wronker chain of department stores, which was “Aryanised” in 1934. They worked together on numerous projects and operated their own hand press. Lili Cassel Wronker has illustrated a large number of books. Her work has been displayed at exhibitions in the USA, England, France and Israel, and she has received numerous awards.