I had a quarrel with my sister just now. I am in a super bad mood. What should I do? Every time you fight over a trivial matter?

Sister also has her own life, and you said it was a trivial matter. Maybe she thought it was entirely possible for her mother to do it, so she did it. And maybe you didn't make it clear to your sister before and didn't want your family to know. This is a small misunderstanding. Maybe you stayed at home for too long and got a little upset, so such a small thing happened to be the fuse. Maybe you'll still be angry with others. Think from the other person's point of view and don't let the other person care.