Are there any novels about siblings that I can recommend?

The older sister was beautiful, mature, and sensible. She had been very good to her younger brother since she was young. Later, the older sister found a boyfriend at work, but the older sister obviously did not treat her boyfriend as well as the younger brother. The boyfriend also said in front of the younger brother that his older sister did not treat her boyfriend as well as his younger brother. When the younger brother asked, the older sister said that she needed a boyfriend outside, which meant that the older sister did not love her boyfriend. There were also scenes of the siblings washing clothes together. One Christmas, my younger brother asked my sister out to a Western restaurant. My sister said that she had already made an appointment with her boyfriend, but she agreed to my younger brother's invitation. My younger brother knew that my sister knew how to solve this kind of thing, so he expressed his true feelings to my sister in the restaurant, and my sister agreed. Then, my younger brother drove to the hotel. That's all I saw. I didn't read the rest. Who knows what happened next...