Is it permissible for me to hit my sister who verbally and physically abuses me and disregards the family's directives, knowing that I am 17 years old and she is 11 years old? If not, then when is it permissible?

We advise against reciprocating your sister's bad behavior in kind; rather, repel it with that which is better, based on the Almighty's saying: "Repel evil with that which is better," and His saying: "Repel evil with that which is better, and thereupon he between whom and you was enmity [will become] as though he was a devoted friend." This requires patience and avoiding discussions and jokes that incite conflict, as her conduct contradicts Islamic manners. You can seek the help of your parents if the matter escalates to physical assault, along with supplicating for her rectification and advising her gently and wisely. We emphasize that disciplining a sister is the father's responsibility when he is present, and the brother should inform him of her immoral actions.