AITA for telling my SIL that I was disappointed in her for not putting up more of a fight in defending herself.

I am 13 years old and will admit that I am not a pretty girl at all. I have always been self-conscious about my looks and not had many friends due to that. My enviroment has not helped to much either as I come from a big family and my parents only have 2 kids, me and my sister, enviroment and extended family says that parents who have only two kids are lazy and do not protect their kids as they do not have enough kids to have their backs. So parents who have 2 kids are pretty much shit parents here. <br><br>Anyway, I am currently living with my brother and his wife. He is a hard working man who spends a lot of time at work and has no problem with me going to school and currently working part time, but my SIL is not a fan of me. <br><br>She grew up in a bigger city and I am a village girl while she used to live in a big city. She grew up pretty, smart and prettier then me. She often says to me things like "Oh, she is much prettier then you". So I have been a target for her. She often says hurtful stuff towards me and belittles me. Not behind my back but right in my face. I have not said anything to my brother as I am scared of what he might think of me for saying that to him. When this incident happened, I told him and he said "I am telling you this now OP, only tell me the truth of what happened, and I will judge from there". I am sad because I do not know if he will believe me or think I am lying.<br><br>The other day SIL was making dinner and I got hungry and decided to make some popcorn. I took the pot out to make some popcorn and then she started screaming at me to get the fuck out of the kitchen. I was making popcorn and she came and slapped the bowl out of my hands, spilled it all over the floor and told me to clean it up. <br><br>I told her "I am going to eat the popcorn, why are you slapping it out of my hands, is it yours?"<br><br>She slapped me and pushed me to the ground, hair first. I started crying because I got hurt by the slap and she grabbed my hair and started screaming that I am ungrateful, that I do not deserve her as she is my only family left in the world and I am being disrespectful.<br><br>She then grabbed me and dragged me outside while I was crying and told me to go and beg my parents to let me come back to them. But I told her that I had nowhere to go and currently had no money to go. <br><br>She told me to go and fuck myself and that she will tell my brother that I am breaking his things on purpose. <br><br>She then shut the door and left me out in the cold. I was hurt and crying so I went to my friends house and told him what happened. He was angry and said that I should have fought back or told my brother a long time ago. I told him I was scared. <br><br>He then offered to let me sleep at his house and he would take me to school the next day and give me some money so I could go home if I wanted.<br><br>I thanked him and he took me to school the next day and took me to the station and gave me 100 USD to take the train and bus to go home. I thanked him and left. <br><br>After a week, my brother came and picked me up saying that his wife told him that I broke a few of his things on purpose and she told him she kicked me out and he said "How could you kick my sister out? she is 13 years old, I told you to take care of her, I am so disappointed in you." She then cried to him and told him everything that happened and he was very disappointed. He told me "You should have fought back. You should have defended yourself. You let her walk all over you and you took the beating. You should have fought back, I am calling you a jerk because you should have fought back." and took me back to his house. <br><br>I am feeling a bit betrayed that he called me a jerk.