You Must Fulfill Your Oath

Question :

I helped one of my sisters get married, and she had three children. She was constantly at odds with her husband.

She was also in disagreement with her father, the cause of which was her husband, who used to treat her in an extremely harsh manner, which forced her to leave the house and go to her divorced mother's house who was now married to another man. Her mother's husband (the second one) treated her in a bad way. So I, her brother, took an apartment for her to live in with me and she used to go often to her mother's house. One time, her mother's husband forced her to discard her children with her husband and so she did it to please her mother. One day, a disagreement took place between her and her mother's husband and she went to her apartment while she was very upset about what had happened and because of the absence of her children. She went there and took some tablets from the refrigerator and swallowed them all, wishing to end her life. So I took her to the hospital and she was given the necessary treatment. Before she died, she sensed that she was in her final days and she repented and asked forgiveness for what she had done.

She asked us to supplicate for her forgiveness, and Allah's Will was implemented, and she died. What is her situation after that? And is it permissible for me to give charity and to perform Hajj on her behalf, bearing in mind that I vowed to perform these deeds for the rest of my life, if Allah wills?

Answer:

As long as this sister of yours turned to Allah, Most Glorified in repentance and regretted the actions she had taken which caused her death, then it is hoped that she will be forgiven. Repentance cancels what passed before it, and the one who repents from a sin is like the one who has no sin, as is proven by the authentic Hadiths from the Prophet ﷺ.

If you gave charity on her behalf or asked forgiveness for her and supplicated for her, that would be good and it would benefit her and you would be rewarded for it.

You must fulfill the acts of obedience you vowed to perform. Allah, Most Glorified praised those who fulfill their vows in His Words:
"They (are those who) fulfil (their) vows, and they fear a Day whose evil will be wide-spreading."

The Prophet ﷺ said:
"Whoever vowed to obey Allah, he should obey Him and whoever vowed to disobey Allah, he should not disobey Him. And Allah is the Granter of success.

Source:
Ibn Baz
Fatawa Islamiyah, Vol. 6 Pages 423-424