Musannaf Ibn Abi Shaybah

Hazrat Sa'id bin Muslim narrates that Hazrat Sha'bi was asked about a person who had been killed and had left behind a daughter, a sister, and two wives, and one of his two wives forgave the blood of her husband. Upon this, Imam Sha'bi said: A woman does not have the right to forgive except for that woman who is a close blood relative (mahram) of the murdered person and has a share in the inheritance.