Based on sociocultural theory, this article examines two activities constituted by a parent and child as jointly constructed bi-literacy practices. Bi-literacy practices enable the parent and child to co-construct conceptual meanings and sense across two languages. Concept development in young children "begins" with meaning in one language and over time develops into multiple nuanced sense in two languages; a process that reflects a developing system of thinking that ultimately enables proficiency in two languages. Using a discourse analytic approach to intertextuality, we elaborate the definition of intertextuality at the level of "interaction" and the level of "utterance" and analyze two transcripts for language form and function. Social practices that engage parent and child in bilingual interactions can be mapped for bilingual intertextuality to highlight the facilitation of concept development, "which begins," rather than ends, with the construction of word meaning. (Contains 2 figures, 1 footnote and 3 tables.)