Social robots provide new opportunities to support general child healthcare programs. However, it is still unclear how social robots could be used in this context and how corresponding behaviours should be designed. To ensure satisfying implementations of such new technological solutions, it is essential to include the end-users in the designing process. We have conducted a co-design study at two primary schools based on three complementary, creative methods: Draw-write-and-tell and/or story-writing-and-telling, Theatre play, and Robot avatar programming. A total of 46 children aged 7–12 years old participated in four robot co-design workshops. The drawings, stories and theatre plays were analysed, resulting in evaluations of 10 scenarios as well as 21 new scenarios and 7 main user requirements for social robots providing mental support in general child healthcare. Evaluation of the activities highlight their stimulation of out-of-the-box thinking and the development of creative solutions (i.e. drawings/stories/theatre plays resulted in robot designs, scenarios and requirements), while children’s reflections show them being enjoyable for participation. The inputs gathered during these co-design workshops will greatly influence future work on the design and application of social robots in the child healthcare domain.