At Oxford, Hughes was encouraged to work in the picture book format and make lithographic illustrations. She was soon commissioned by book publisher William Collins, Sons to illustrate another writer's book. During the 1950s and 1960s, she worked primarily as an illustrator for the books of other authors, including "My Naughty Little Sister" by Dorothy Edwards and "The Bell Family" by Noel Streatfeild. The first published book she both wrote and illustrated was "Lucy & Tom's Day", which was made into a series of stories. She went on to write over fifty more stories, including "Dogger" (1977), the "Alfie" series (1977), featuring a young boy named Alfie and sometimes his sister Annie-Rose, and the "Olly and Me" series (1993).