What is the term used for a woman who creates a last will and testament?

The term for a woman who creates a last will and testament is "testatrix." This term specifically refers to a female who has executed a will, identifying her as the individual responsible for dictating how her assets and affairs should be handled after her death.

In legal terminology, the male equivalent is "testator," which applies to a man who creates a will. The gender-specific terms help clarify the role of the individual in the context of estate planning and testamentary instruments.

Other terms such as "heir" and "beneficiary" refer to those who will receive the assets or property upon the passing of the testatrix, but they do not denote the person creating the will. An heir typically inherits under the laws of intestacy when someone dies without a will, while a beneficiary is someone expressly named in a will or trust to receive a portion of the estate. Thus, "testatrix" is the appropriate term to denote a woman who drafts a will.