Is it permissible for a sister to pay off her poor sister's debt from her Zakat money, given that she does not spend on her?

It is permissible to give zakat to a sister who is unable to pay her debt, as she is considered among the gharimin (those in debt) who are eligible to receive zakat. The funds must be withdrawn from interest-bearing banks, and the interest earnings must be disposed of by spending them on charitable causes and for the poor and needy.