Gender stereotypes facilitate people’s processing of social information by providing assumptions about expected behaviors and preferences. When gendered expectations are violated, people often respond negatively, both on a behavioral and neural level. Little is known about the impact of family kinship on the behavioral and neural reactions to gender-stereotype violations. Therefore, we examined whether parents show different responses when gender stereotypes are violated by their own children versus unknown children. The sample comprised 74 Dutch families with a father (Mage = 37.54), mother (Mage = 35.83), son and daughter aged 3-6 years. Electro-encephalography (EEG) measurements were obtained while parents viewed pictures of their own and unknown children paired with toy or problem behavior words that violated or confirmed gender stereotypes. In half of the trials, parents evaluated the appropriateness of toy-gender and behavior-gender combinations. Parents showed stronger LPP amplitudes toward gender stereotype-violating behaviors by own children compared to unknown children. Moreover, parents’ P1 responses toward gender stereotype-violating child behaviors were stronger for boys than for girls, and for parents who evaluated gender-stereotype violations as less appropriate than gender-stereotype confirmations. The findings indicated that gender-stereotype violations by parents’ own children are particularly salient and viewed as less appropriate than gender-stereotype confirmations.