Is a woman obliged to fulfill her vow to slaughter a ram and distribute it to the poor after the relief of her husband's hardship, knowing that she is no longer married to him and the divorce occurred before the hardship was relieved?

This type of vow is prohibited because it neither brings benefit nor wards off harm. However, it is obligatory to fulfill it once the desired outcome is achieved. If the reason for the vow was compassion for the husband because he is the father of her children, her cousin, and so on, then fulfilling it is necessary, as the motive for the vow still exists. But if its reason was marital affection, love, and mercy that Allah has placed between spouses, then it is not obligatory to fulfill it, because its reason ceased before the desired outcome was achieved due to the termination of the marital relationship.