What is the legal consequence if an Umm Walad kills her master?

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If an Umm Walad kills her master, she is manumitted because her ownership cannot be transferred, and her master's ownership ceases upon his death, making her free, just as if someone else had killed him. She owes the value of her person if Qisas is not obligatory upon her. This is the position of Abu Yusuf. The basis for this is that the injury is inflicted by an Umm Walad, so no more than her value is due, similar to when she injures a non-relative. Furthermore, the status considered for liability in an injury is the status at the time of the injury. Because she forfeits her slavery through killing her master, it is analogous to a Mukatab (a slave contracted for freedom) forfeiting his status by fulfilling the contract.