This mixed-methods, quasi-experimental efficacy study evaluated Just Right Reader's Take-Everywhere Literacy Packs™ with 399 kindergarten students across six schools in a diverse Texas district during the 2024-2025 academic year. This district had a consistent curriculum and access to decodable books, however treatment students received the personalized, take-home, decodable book packs and literacy resources from Just Right Reader. Treatment students (n = 233) significantly outperformed comparison peers (n = 166) on end-of-year DIBELS composite scores ([beta] = 10.43, p < 0.001, Cohen's d = 0.393), representing approximately 3 additional weeks of literacy growth over one semester. The treatment students showed significant subdomain growth in letter naming, letter sounds, and phonemic awareness. Qualitative findings from educator and parent surveys and school administrator interviews revealed high satisfaction among stakeholders, with 89% of parents and 95% of teachers reporting improvements in student literacy skills, confidence, and engagement, including notable gains for emergent bilingual students. Results suggest that personalized decodable texts used for instruction during the school day, combined with family engagement tools, effectively extend research-aligned literacy practice beyond the classroom and accelerate early reading development.