This study investigated nutrition quotient (NQ) scores of 283 Vietnamese marriage migrant women and their children in Korea and analyzed the influence of maternal dietary adaptation factors on children's dietary quality. The survey was conducted from February 3, 2025 to February 28, 2025. Based on the acculturation theory, mothers were classified into five dietary adaptation types: complete-assimilation, mixed assimilation-separation, integrated-separation, marginalization, and passive-adaptation. Among preschoolers, the complete-assimilation type had the highest total scores of balance (89.0) and practice (83.4), the lowest score of moderation (30.8), and the highest overall NQ-P score (77.8). Among preschool children, the passive-adaptation type showed the lowest total scores for all domains except moderation. In school-age children, the mixed assimilation-separation type had the highest total scores, while the passive-adaptation type had the lowest scores across all domains except moderation. Among mothers, the complete-assimilation type had the highest total scores in balance (88.0), moderation (66.1), and practice (89.6) domains with, the highest overall NQ-A score (82.1), while the passive-adaptation type had the lowest total scores in all domains except moderation. These results confirm that maternal dietary adaptation can affect children's dietary quality highlighting the importance of dietary education and support for mothers during this stage.