In Chinese culture, the eldest daughter and the eldest son shares different responsibilities within the family in the old days.
In modern society, the eldest daughter is no longer just limited to her traditional responsibilities. Many of them also increasingly find themselves required to take on the part of the eldest son, such as sharing the financial burden of the family, or any of a number of other roles that parents used to only expect from the eldest son. Being the eldest daughter in my family, I feel the pressure to do more, and likewise, other eldest daughters also share similar pressures from their parents in different ways.
Parents generally do not expect the eldest son to take on the traditional roles of the eldest daughter, such as carrying out household chores. The perceptions of society are changing, and as a result, a new version of the same dynamic is created. Parents are giving preferential treatment to boys in a different form. The traditional identity of the girls is getting eroded because Chinese society is now expecting the girls to be like boys, and sometimes girls may need to abandon what has been expected from them in the past, in order to fulfill their new roles.