Some of her mother's bank earnings paid for her education
23-6-2003 | IslamWeb
Question:
I would like to ask you about two things: 1) My mother was working in a bank now she is retired and a part of her work was Halal can she eat from this part? 2) My mother was helping my father for my education, so is my diploma Halal or Haram? I feel that I don't have the right to work with it. So what must I do? Can I give the money that equals what my mother spent to the poor and work with my diploma?
Answer:
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 
is His slave and Messenger.
Dear Brother,
There is no harm that your mother spends from the lawful part of her earnings provided this part is identified.
There is no doubt that her work in the Riba (interest and/or usury) bank was forbidden and that the salary she got from that was forbidden as well. The Prophet said: “Allaah has cursed the one who consumes Riba (i.e. usury or interest), the one who gives it to others, the one who records it and the one who witnesses it (its transaction).” He said: “All of them are equal in sin.” [Muslim[
On the other hand, there is no objection to your benefiting from your diploma. In fact, when somebody earns something in an unlawful way and consumes it, he should only repent to Allaah and have remorse for what he did.
Ibn Majah and Imaam Ahmad, 
reported a Hadeeth considered sound by Al-Albaani and Al-Arna’oot that the Prophet said: "Remorse is repentance."
What is mandatory is to get rid of the forbidden earnings if one actually has them in possession. But what was spent on education fees is no longer under possession.
As for how to get rid of unlawful earnings, it is done through giving them to the needy and the poor or spending them in the general benefits of the Muslims. An-Nawawi 
even stated in his book Al-Majmoo’ that one could spend from the unlawful earning he has on his children provided they are poor.
Allaah Knows best.