Family & Friends

My mom was badmouthing my sister and now she's mad at me?

So my family really doesn't get along well and my parents especially get mad at my sister these days. So a couple of hours ago, I was sleeping but I was like half-awake so I could hear stuff. My sister was gonna go to work then stuff I didn't understand happened and my parents got really mad at my sister. Once again, I was half awake, so I don't really know what was happening, but I knew that it wasn't good.

Anyway so I later started having breakfast with my mom and it was all chill cuz I was trying not to get her mad. But then my brother mentioned my sister and my mom started getting mad. She was saying things like how she never wants to see her again and how my sister should pack her things and go (by the way my sister is 16). So then I got mad cuz I didn't like the way she talked about my sister. I told my mom not to say that stuff in front of me cuz it hurts and she literally didn't even understand why it bothered me. She was like "when someone talks to you, they want you to listen, so you have to listen, whether you want to or not". So then I got angry and I was like "how do I know that you don't say things about me and my brother behind our backs". Then she left the table and went to her room. I swear, my mom has these freaking mood swings and they're disgusting. My parents always call my sister a drama queen but my moms an even one. Anyways, now she won't even talk to me and when she's in this like depressed mood, she stays like that for a while. It's really disgusting. Anyways so I really have no idea what to do. Any advice?
My mom was badmouthing my sister and now she's mad at me?
Post Opinion