Is it permissible for the wife to secretly waive her right to retribution (Qisas) in exchange for money without the knowledge of the slain person's family? And in this case, is the wife considered an heir by blood? And what are the rights of the slain person's family if retribution is waived?

Retribution (qisas) is a right of the victim's guardians (awliya' al-dam). Scholars have differed on whether this right is established for them originally or through inheritance, and on who among the heirs is entitled to it. The preponderant opinion is that retribution is first established for the victim, then transfers to all their heirs (men and women, adults and minors) like their other assets. If one of the heirs waives their right to retribution, the right to retribution is forfeited, but others retain their right to blood money (diyah). The wife has the right to waive her right to retribution, and by doing so, the right of the remaining guardians to retribution is waived, and their right shifts to blood money. Waiving retribution is closer to piety and an expiation for the one who does so. What the wife receives in exchange for waiving retribution has no bearing on her share of her husband's inheritance; she receives her full share of the inheritance (one-fourth). Scholars have differed on who is entitled to the money received in reconciliation for waiving retribution, and the preponderant opinion is that all heirs who have a right to retribution share in it.