Although the daughter-in-law is not the first heir, in order to maintain family harmony and encourage respect for the elderly, the law stipulates that under legal circumstances, the daughter-in-law can also become the first heir to inherit the parents in law's inheritance.
 1. Widowed spouse can become the first heir after fulfilling the main maintenance obligation
 (1) According to the provisions of the Marriage Law, only the legitimate children, grandchildren and grandchildren of the elderly have the statutory duty of support, and the spouse of the supporter has the duty of assistance. If the marital relationship between the supporter and the spouse does not exist, the spouse does not have the duty of support.
 (2) Our country only stipulates that in the case of widowhood, the daughter-in-law can be the first legal successor if he or she has made the main maintenance obligation to his or her mother-in-law. In other cases, the daughter-in-law cannot inherit the inheritance of his or her mother-in-law.
 (3) Even if the daughter-in-law can become the first heir, if the parents in law make a will or a legacy maintenance agreement to arrange the property to others, the daughter-in-law still cannot obtain the property, nor can they claim compensation from the parents in law.
 2. How can we fulfill our main maintenance obligations
 "Widowed daughter-in-law shall do the main duty of support" is not simply to see the elderly, but to take care of the elderly regularly for a long time. If the elderly have other children to take care of, or can take care of themselves, it is not a major maintenance obligation, which is specifically shown as
 (1) Provide the parents in law with the main source of economic life, properly arrange the living conditions of the elderly within the scope of economic conditions, and provide living expenses, medical expenses and other expenses.
 (2) Providing major daily labor services to parents in law, and providing emotional and physical support to the elderly, including daily food, clothing, and nursing care when ill, can not be regarded as fulfilling the main support obligations if only providing financial support.
 (3) Even if the daughter-in-law remarries after losing her spouse, if she can provide the parents of the deceased with major financial resources and daily labor assistance, she can also become the first heir in line.