Assalamualaikom my brothers in Islam. I would like to know the fatwa of having stepmother, which happened to be a mother's biological sister, who is drastically treating her nephew and her nephew's wife because she was against of the marriage. The worst of it is she had convinced her sisters to be against their own nephew. On the otherside, the nephew had mistreated his stepmother before the marriage but he had deeply repent and apologized to his stepmother. To avoid confusion, the real mother of the nephew has already passed away before the marriage of his father to his stepmother. Your immediate answer is highly needed. Jazakallahu Khairan.

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, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

It is Islamically required from the Muslims to work towards achieving harmony and love between them and avoid the causes of disputes. This matter is even more confirmed between relatives, as Allaah enjoined upon them to maintain ties among themselves and forbade them from severing ties with each other. Allaah even considered severing ties with kinship as corruption on earth, Allaah Says (what means): {So would you perhaps, if you turned away, cause corruption on earth and sever your [ties of] relationship?}[Quran 47:22]

Therefore, all Muslims are obliged to fear Allaah in themselves and fear Him in regard to their relationship with each other.

Based on this, if this woman is just the wife of the father, she has the right to be respected and honored, as honoring her is like honoring the father, so what about if, in addition to this, she is a maternal aunt. Indeed, the maternal aunt has the same status as the mother as confirmed in a Hadeeth.

However, if she really mistreats her nephew and his wife, and convinced her sisters to be against their nephew, then she is negligent about the rights of kinship and she is disobedient to her Lord. Hence, she should be advised and reminded of Allaah and warned against His Punishment.

In any case, we advise you to be patient with her and supplicate Allaah to rectify her. We also advise you to endeavor to reconcile between yourself and her as this is one of the acts of worship by which one gets closer to Allaah. Allaah Says (what means): {No good is there in much of their private conversation, except for those who enjoin charity or that which is right or conciliation between people. And whoever does that seeking means to the approval of Allaah — then We are going to give him a great reward.}[Quran 4:114]

Allaah also Says (what means): {… and settlement is best.}[Quran 4:128]

Besides, Abu Ad-Dardaa’ narrated that the Prophet said: “Shall I inform you about what is better than the degree of fasting, praying and giving charity? They (the Companions) said: “Yes (O Prophet of Allaah)” Thereupon, the Prophet said: "Reconciliation, because spoiling the relations between the kinship is the shaver (the destroyer, i.e. it destroys religion).” [Abu Daawood]

In doing so, one may seek the help of rational and virtuous people, either among relatives or other people.

Allaah Knows best.