On the basis of a longitudinal survey, this article assesses the challenges posed to the educational norms and practices of parents with higher education by the birth of their second child. By focusing in particular on the norm of the singularisation of children and that of equal treatment, we show in concrete terms how parents welcome their second child, the place they give to the child in the family, and how they are led to set their sights lower in terms of the practical realisation of their objectives on education. Calling for considerable parental involvement and availability, the implementation of these norms hinges on the input of mothers and serves to reinforce the unequal division of parenting and domestic work on the arrival of a second child. This growing inequality makes it more difficult in turn to accomplish these educational norms.