A woman who has yet to make a son is the lowest of the low, far beneath her mother-in-law. Once she produces a male heir, she increases her status in the family, in her husband's eyes, and as the mother of the father's child, thus reducing the status of the mother in law and her power over the girl as well. Before, her own mother only spoke of the future without her, in her brother's terms, and only when married does she have a future -- but with a past door of her childhood "slamming shut."(243) Question

This creates a fragmented household, pitting woman against woman, all eyes turned to the husband for authority. And before, in a house with daughters, no "matter how fond of his daughter the father may be" she is a temporary member of his household, with no ties to him, and she will not protect him in his own old age."...

Also, because the son will take care of the family until his parents die, "he is identified with the family," unlike the daughter, whom is almost like an unwelcome guest, eating and requiring care, but providing no material value in a stable fashion. Thus, there is an additional, personal incentive to produce sons for women, not only for immediate status, but also with an eye upon their long-term care. (241)