Research shows that epistemic cognition can support reasoning about the inclusion of diverse children. We argue that, to engage in such reasoning, children need the capacity to consider and evaluate competing knowledge perspectives (epistemic cognition) and to be cognitively flexible. Cognitive flexibility involves a subset of skills within the suite of self-regulation skills known as executive functions (EF). This study explored the extent to which cognitive flexibility might be related to epistemic cognition and the effectiveness of a pictorial and interview methodology to explore children's epistemic cognition. Eighty-two children participated in three EF tasks designed to assess their ability to flexibly shift from one mental set to another (cognitive flexibility). Children were also interviewed about the drawings they created to represent social exclusion/inclusion in their play settings. Results indicated that, in contrast to expectations, cognitive flexibility and epistemic cognition were not related. Challenges associated with using the pictorial and interview methodology are discussed.