While previous studies have highlighted the benefits and challenges of bilingualism, limited research has explored how parents perceive the different factors that may contribute to a child’s speech delay in multilingual environments. Little is known about how parental beliefs and home language practices shape speech development when a language becomes dominantly spoken. This study examined a parent’s lived experience to understand how language choices, daily interactions, and beliefs influence the speech development of a multilingual child with a diagnosed speech delay. Specifically, it explored how parental language practices affect speech development and how English dominance interacts with other home languages. A qualitative design using narrative inquiry was employed, focusing on a mother’s account of her son, Samuel. Data were collected through a semi-structured interview and triangulated with records from a therapy center and a welfare office in X City. Thematic analysis, guided by an interpretive and story-based approach, identified patterns in parental practices and the child’s developmental outcomes. Findings showed that Samuel’s speech improved through early diagnosis, structured therapy, and consistent parental involvement. English became dominant due to early exposure, providing a stable medium of communication. However, the delay was not caused by English dominance itself, but by limited parent–child interaction, excessive screen time, and inconsistent multilingual input. Meaningful engagement, guided language practice, and balanced exposure to all languages supported progress. Although focused on a single participant, the study offers insights for parents, therapists, and educators supporting children with speech delays in multilingual contexts.