The aim of the article is to deepen the research on the inter-relations within the most influential families and their members in the eighteenth-century Grand Duchy of Lithuania by attempting to look at the relations between mothers and their children, particularly sons, through the prism of ego-documents: by examining the women’s letters written to the spouse, their mother-in-law, and children. The heroine of this article is Franciszka Urszula Radziwiłłowa z Wiśniowieckich, (1705–1753), the spouse of Michał Kazimierz ‘Rybeńko’ Radziwiłł, one of the most influential Lithuanian noblemen of the time. Her literary works and cultural activities have been extensively studied in Polish (less so in Lithuanian) historiography. These studies introduce Franciszka Urszula as a creator, a wealthy matron, and the wife of an influential nobleman. Yet in her letters to her husband, she reveals herself as a very sensitive and loving woman, full of anxiety
and concern for the well-being of her husband and children. The analysis of the duchess’s correspondence of 1734 to 1746 attempted to answer, among others, the following questions: what did the correspondence of the noblewoman reveal about family relations? How did she fulfil her role as a mother? How significantly was she engaged in the upbringing and education of her sons?