I need some advice

Haly • 1 angel baby 👼🏼 20 mama to a 1 year old baby girl TTC #2!

Hey guys let me start this out by saying I’m 18 and my sister is 15. My sister has ADHD and dyslexia which for people who don’t know basically makes it difficult for her to figure out what right from wrong is and sometimes she can get out of control. She has hit me on several occasions which I have showed my mom the marks or I’ll video tap her because when I don’t come back with something she says “well how am I supposed to know your telling the truth.” Which I get ok so I video tap her when she’s either hitting me, cussing at me, or just in general misbehaving like when she got in trouble she was kicking her wall which was knocking my stuff down I asked her to stop and she did it harder. I always hold onto my anger because I know when I go to tell my mom I can’t have done something back but I’m getting fed up when I tell her somethings she’s done and it’s usually pretty extreme when I do go to her like when she’s hitting me she does it all the time and my mom knows I have marks all over me when I go to her. She’ll take her phone away for 30 minutes and my sister will start crying and throwing a fit or she’ll say she’s having a hard time today and can she call her friend. Her punishments are just so little and I’m not even sure what to do any more she’s just doing this non stop because nothing happens and it’s not only to me she’ll give my dad attitude or my brother anyone and when we try to say something back she’s just like shut up I’m done talking to you and nothing happens is it bad that I’m expecting more I tried to talk to my mom and she just always says well your brother thinks I don’t punish you enough. So I say ok go ahead but you know you treat her differently then me then she’s like ya because we expect more from you can someone just please give me some advice I’m sorry for the long post but I’m not sure where else to post this.