The Polish diaspora’s commitment to maintaining its cultural and linguistic heritage in foreign environments not only enriches their communities but also deepens the understanding of diaspora dynamics in cultural preservation. This article analyzes the narrative development of Polish-speaking children as a means of supporting the maintenance of the Polish heritage language (HL) in Finland. The case study focuses on a family with a visually impaired father and three children. The material was drawn from interviews with the parents, books created by the children on their own initiative, and picture book narratives. Using an ecological approach and narrative analysis, the study explores how children naturally expand their competence in Polish through storytelling. By fostering storytelling skills, children strengthen their linguistic, cultural, and emotional connection to their HL. Narratives enable them to use Polish in meaningful, everyday contexts, creating a natural environment for language practice. Through stories that incorporate elements from Polish, Finnish, and international settings, children develop intercultural awareness, adaptability, and a deeper appreciation for their Polish roots. Storytelling between parents and children in Polish also fosters emotional closeness and reinforces the family’s linguistic bond. It encourages children to communicate with Polish-speaking relatives, such as grandparents, thereby supporting intergenerational language transmission.