Early writing is a critical factor in children's literacy development and academic success. This study observed and analyzed videos from twenty-eight teachers working in prekindergarten, kindergarten, and first-grade classrooms in under-resourced schools. The coding process focused on categorizing the type (language- and code-based) and demand (low- and high-demand) of strategies that teachers used to support children's development of the foundational skills for early writing. We use the Not So Simple View of Writing as a framework to outline which writing-related skills (specifically, vocabulary and literacy) are important to explore. Multilevel models explored unique links between teachers' (N = 28) supports for various early writing-related component skills, as well as children's (N = 324) vocabulary and early literacy outcomes. The findings demonstrated that, regardless of grade level, teachers tended to emphasize code-based skills over language-based ones as children composed. Multilevel models showed that the vocabulary and literacy skills of children improved in classrooms where teachers provided higher levels of both high-demand language- and code-based writing support. The findings indicate that teachers' support for children's translation and transcription processes during composing may result in reciprocal and mutually beneficial effects on the foundational component skills of writing.