De Gruchy established a design studio "Craftsman's Market", Toowong, QLD in 1962 offering design goods such as Marimekko & Danish-inspired furniture. Her husband, Graham de Gruchy also designed furniture for the shop. In the 1970s, she began supplying interior design services, later serving on the Crafts Board of the Australia Council. She and her husband established the Darnell-de Gruchy Art Prize, University of Queensland.