Little sister, I can only say that your sister-in-law has a big personality problem! She doesn't know how to be grateful, understand and tolerate. You put up with this kind of person, she thinks you are a fool. As you can tell from your description, you got up at 5 am and took care of her like a servant. She doesn't have a good word, and even satirizes you, your brother and your parents with the normal acne phenomenon in adolescence. I really don't know if this kind of woman is ugly or if your brother is greedy for her family. At first you thought your sister-in-law was good, but later you thought she was bad. I think there are two reasons. First, she wants to marry into your family and definitely wants to get on well with you. Second, you are too kind to her, but she has a sense of superiority and looks down on you. I suggest: 1. No matter who you are, everyone is equal. You should be good at expressing your thoughts to her, don't just endure it. 2. Read more books when you are free and go out to find friends. Students should concentrate on their studies. If you can't handle the family relationship well, put it aside and don't affect your study. No one will dare to tell you what to do easily when you are admitted to university and find an economically independent job.