Within-family differences in parenting (PDT (parental differential treatment)) can be accompanied by children’s perceptions of parental favoritism. Perceptions of fairness of PDT are essential, however, little is known on how children legitimize PDT. We used focus groups and individual interviews to explore children’s (N = 16) differential experiences. Interviews were transcribed and analyzed using a hybrid deductive-inductive approach. Questions targeted: (1) domains of PDT; (2) explanations of PDT; and (3) considerations of fairness. The results show that siblings gave examples of differential affection, control, time involvement, privileges and household responsibilities, but additionally expressed responsibilities in care of each other. Three explanatory categories were added to responses of previous child samples: birth order, sibling relationship quality and biological relatedness. Fairness-considerations comprised a cognitive and emotional component and moderating factors. Equity was obtained through parents’ responsiveness to child and family characteristics and through compensating strategies, such as turn-taking. Children are able to acknowledge and legitimize PDT. Parents’ differentiation does not preclude siblings’ perceptions of equal treatment.