Why does my husband's family always let me cook during the Spring Festival, not my sister-in-law? I haven't thought about any good things, just thinking about my sister-in-law. What do you mean?

Maybe it's because eldest sister-in-law spends more time with her mother-in-law than you do, and she is better at being a person. The relationship between two people is better. You are a junior in this family. As you can see from your speech, you are not the kind of smooth person, and your relationship with your mother-in-law is definitely worse than your sister-in-law. And if you don't live with your mother-in-law, it's understandable to go back and let you do something once in a while. Stop complaining, it's much better than living with your mother-in-law every day.