Who is more right here?

My younger sister, eighteen, came to my room and said, "Will you come shopping with me? I need food for tomorrow." She said, "Now I have to get dressed right away, and we should leave because they close at 9 p.m." I told her at first, "Why me?" and then saw that the store didn't close until 10 p.m. after I checked before she did. But she said, "But I want to go now." Then I wanted to tell her, "Give me 10 minutes and I'll be ready," but she stormed off before she could hear me.
Then she went to my mother to complain about me. I called her, but then I thought, that's her problem, that she wouldn't listen to me. And then I didn't get ready, so I told her, "I wanted to tell you that I was getting ready, but you left." "We never said whether we were leaving now or not." And then she said, "But that was fifteen minutes ago." Yes, I thought she hadn't heard that, she hadn't told me whether we were leaving now or not. Then she took advantage of my tired mother, who worked with her to make me look like the bad person. Who has more rights here?