Is it permissible for a woman to give the Zakat on her wealth or its profits to her needy son or daughter?

It is not permissible for a mother to give her Zakat to her son if his maintenance is obligatory upon her. However, if it is not obligatory and he is poor, then there is no impediment. As for usurious gains, they are ill-gotten wealth that should be spent on the general welfare of Muslims. It is permissible to give them to the needy poor, including the children of the person who possesses this money.