This article synthesizes multiple studies that we have conducted on language and literacy practices among Latinx siblings at home, and identifies implications for teaching. Examples from micro-ethnographic discourse analyses provide rich vignettes of sibling interactions within Mexican and Central American immigrant households to illustrate how siblings engage in complex negotiations as they language together at home, in English and Spanish. Older siblings provided unique scaffolds for younger children's learning and development in ways that demonstrated broad and flexible expertise, but these practices also reflected the complex social and linguistic circumstances in which immigrant-origin Latinx children live. Findings suggest that teachers can play active roles in supporting language and literacy development inside and outside classrooms.