How much of her deceased father’s property could an unmarried daughter obtain? During the Northern Sung, according to the Sung Codes, the amount was only half the value of her brother’s betrothal gift. During the Southern Sung, as seen from a few cases in the Enlightened Judgments of the Renowned Judges, it was half the value of her brother’s inherited property. How can we explain this big change, which was in fact a reduction of the brother’s share to increase the sister’s. Simply put, the brother’s loss was the sister’s gain (少給男以多給女). Researchers must bear this in mind to avoid missing the most important point in explaining the change. Recently some researchers suggested that the change was aimed at benefitting the orphaned children. For example, Takahasi Yoshiro (高橋芳郎) maintained that it was for the older sister who gained in the inheritance to take care of the orphaned junior brother who lost, while Hsing T’e (邢鐵) argued that it was not the brother, but the orphaned junior sister who was being cared for. Readers may wonder how researchers studying the same law and using the same legal cases could have come up with totally different answers, in particular regarding the gender of the beneficiaries. This essay has three goals. First, to prove that the new law of the Southern Sung was not aimed at benefitting any orphaned child, male or female. Second, to explain the legal cases anatomically in order to preempt further misunderstanding, describe some research experiences, and provide methods for younger researchers. Third, to clarify some legal concepts, like “heirless family” (戶絕) and “inheritance by subrogation” (代位承分) to avoid further distortion or complication of historical data.