The painting of a Rainforest was one of the final pieces Joanna produced for her portfolio whilst at Falmouth Art College and which she used when approaching different publishers in London to be appointed as an illustrator. It was also reproduced on the front of large, printed cards sent to potential agents and publishers, as an example of her work. Before she graduated in 1991, the rainforest card resulted in her being booked by a London agent called The Garden Studio.
The Garden Studio represented her for her first year’s work until she decided to go her own way as she was by then, being approached directly by many publishers. From 1991 to 2021 she worked for many different publishers producing realistic illustrations which were mainly animals from all round the world. She often went to libraries to look up references or to visit zoos to photograph certain species. Outside this, she also illustrated books about dinosaurs, plants and insects.