Is it permissible to pay off personal debts using bank interest, and is it permissible to give this interest to a needy sister?

It is not permissible to deposit money in interest-bearing banks, and the mother must repent and withdraw the money from the bank unless there is an extreme necessity. She must also dispose of the usurious interest by spending it on public welfare. It is permissible to give from these interests to the son, daughter, father, and anyone whose maintenance is obligatory upon her, to pay off their immediate debts if they do not have the means to pay them or if they become destitute after paying them off.