Early childhood poverty is a prevalent social issue, both in the United States and in the wider international community. It has been well established that factors associated with poverty, including familial income and parental education level, can negatively affect children’s language and cognitive development, which can result in academic achievement deficits that compound across the lifespan. Additional environmental factors, specifically maternal and children’s own social–emotional development, have also been shown to impact these sensitive early childhood developmental processes. Although individual components that relate to language and cognitive development in young children have been identified, additional examination of potential associative relationships between these components is warranted. Therefore, this study explored socio-economical, health, and developmental relationships between 122 caregiver–child dyads enrolled in an Early Head Start Program where children were 1–36 months old. Results indicated strong bidirectional correlations between children’s cognitive and language development. Multiple linear regression path analysis indicated that children’s cognition and social–emotional wellbeing have a significant direct effect on their language development. Additionally, language and fine motor development were found to have a significant direct effect and social–emotional wellbeing mediated an indirect effect through language on children’s cognitive development. In light of socioeconomic and sociocultural challenges, the importance of nurturing children’s social–emotional development in relation to language and cognitive development is discussed.