Recent study on gender representation in children's literature has focused on the representations themselves, while there is less research regarding how children talk about these depictions in texts. Our work, a qualitative study of how kindergarten-aged children discuss gender during picture book read-alouds, examined how children drew on the social binary of boy/girl as they made sense of the human and non-human characters' identities. The study looked at how children responded to questions about gender across both ambiguously-gendered characters and texts where gender norms were deliberately questioned. The findings expressed in this paper provide insight into how students' previous experiences, along with classroom norms and text choice, influence student response. Specifically, we found that children drew on similar social norms and gendered expectations across all character types, demonstrating the importance of these societal categories on their comprehension of texts and on their sense-making of their lives and classrooms. The paper ends with implications for early childhood educators in allowing for more diverse representations when selecting texts and deliberate listening to student conversations to recognize how young learners perceive gender and identity.