Is it permissible to give zakat to the children of the widowed wife who do not live with the husband, and whose guardianship is with their grandfather?

It is not permissible to disburse zakat (definition) to orphans if they are wealthy from their own money, or if their grandfather is able to provide for them, because they are self-sufficient. This is by agreement of the Shafi'is, Hanbalis, and Hanafis. As for the Malikis, they hold that it is permissible to give them zakat even if their grandfather provides for them, because the grandfather's expenditure on them is considered a voluntary act, as the obligatory expenditure for children is only upon the direct father.