In this article, I argue that parental privacy has often been given too much weight in theorising about justice at schools. Susan Okin famously stated that as the family serves as the children's 'first school of justice', it should also be internally just. However, she agreed with John Rawls on that interfering directly within the family life, even in the name of equality and justice, would risk causing injustice to those who do not share these liberal ideals. I ask in what sense this principle of non-intrusion into the private should be extended over the school institution. If the principles of public justice and private morality came into conflict in school education, which set of principles should be given priority? I pose Rawls' suggestion concerning children's schooling against his depiction of the family and claim that these two are normatively at odds with each other. Of the two, the latter seems paradoxically to allow for more extensive public regulation and therefore his view of the school must be modified accordingly. Moreover, I revisit one of Okin's main arguments that countering injustices requires active and explicated countermeasures where education plays a key role. Therefore, it is justified to prioritise principles of public morality, and teach related substantial values at schools, given that they accord with the demands of justice. Parental privacy applies to schools only in a limited sense.