My father wants to offer an Udh-hiyah (sacrificial animal) on behalf of my married sister. As well known, the Udh-hiyah is to be divided into three parts. As regards the part that is for the family, to whom should it be given, to the family of my father or to the family of my sister?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

If your father wants to offer a separate sacrificial animal, other than his, on behalf of your sister, then this is permissible and valid if her permission is taken for that. Thus, the Udh-hiyah becomes hers, and she may do with it whatever is recommended; giving in charity, giving to others as gifts, and eating from it. This is applicable whether she is independent and lives in her own house, as is apparent, or whether she lives in her father's house. If she is independent and lives in her house, then she may keep the mentioned part and may even keep the whole meat, since the Udh-hiyah is hers and was offered from the money of her father. Also, she may give all of it in charity. However, what is recommended, as we have mentioned, is to combine giving charity to the poor, offering gifts to neighbors and friends, and eating from it. If, however, what is intended is that he wants to make her a partner in his own sacrifice, then this is not valid, given her independence from him in a separate house.

Allaah Knows best.