A defining feature of language lies in its capacity to represent meaning across oral and written forms. Morphemes, the smallest units of meaning in a language, are the fundamental building blocks that encode meaning, and morphological skills enable their effective use in oral and written language. Increasing evidence indicates that morphological skills are linked to literacy outcomes, including word reading, spelling and reading comprehension. Despite this evidence, the precise ways in which morphology influences the development of children's literacy skills remain largely underspecified in theoretical models of reading and spelling development. In this paper, we draw on the extensive empirical evidence base in English to explicitly detail how morphology might be integrated into models of reading and spelling development. In doing so, we build on the perspective that morphology is multidimensional in its support of literacy development. The culmination of our efforts is the "Morphological Pathways Framework" -- an adapted framework that illuminates precise mechanisms by which morphology impacts word reading, spelling and reading comprehension. Through this framework, we bring greater clarity and specificity on how the use of morphemes in oral and written language supports the development of children's literacy skills. We also highlight gaps in the literature, revealing important areas to focus future research to improve theoretical understanding. Furthermore, this paper provides valuable theoretical insight that will guide future empirical inquiries in identifying more precise morphological targets for intervention, which may have widespread implications for informing literacy practices in the classroom and educational policies more broadly.