多年媳妇熬成婆 After many years, the daughter-in-law becomes the mother-in-law. The Handian dictionary explains that after long hardship, a person finally gains a certain standing or position. Its example comes from Li Guowen’s novel Garden Street No. 5: “By seniority, the daughter-in-law of many years has become the mother-in-law. Now it is his turn to be in charge.”
Taiwan’s national dictionary gives a modern example: “He worked hard at the company for more than ten years and finally became general manager.”