For parents in a binational family, fostering bilingualism presents a unique challenge. What does successful bilingual upbringing look like? This study examines 65 European parents who are raising their children bilingually, specifically focusing on the mothers or fathers who represent the non-community language, that is, the language considered foreign in the country where they live. The focus is on the educational period of the first six years of the boys' and girls' lives. The OPOL (One Person - One Language) principle is particularly taken into account in the evaluations. The descriptive study centers on psychological factors, based on the insights of John Bowlby's attachment theory. The study addresses questions such as: What role do elements of attachment quality between parents and child play in successful bilingualism? Do factors like proximity to the child or sensitivity towards the child have an impact on bilingual education?.