Research Framework: The present article analyses lesbian-headed families’ relation to the children’s origins in Italy and Belgium, two countries characterized by their completely different legislation in terms of recognition of biogenetic and intentional origins. Objectives: The goal is to understand and articulate the relationships that families develop to children’s origins as a function of the country’s treatment of lesbian-headed households, of the generation the research participants belong to and of their reproductive path. Methodology: The article is based upon two local studies realized between 2016 and 2020 with 16 families. The methodology adopted includes participant observation of family practices, biographical interviews, informal conversations, the charting of the construction of kinship in each family’s case and an analysis of the legal context. Results: The trajectories of families from different countries and generations show that the relation to the children’s origins is built through time without necessarily breaking with either the past (and foreign) or the local culture of kinship. The context and the particular conditions it creates do, nevertheless, influence this relation. Conclusions: The study reveals an increasingly plural and indeterminate boundary between kin and not-kin resulting from an often incomplete negotiation, a constant redefinition among different actors, and often leading to contradictory practices. Contribution: The article argues that kinship assumes different forms according to the actors and to the dimensions at stake (juridical, social or experience), as well as to the generation the mother belongs to.