Any advice

So I’m 21 I have 3 younger siblings one is a 13 yr old girl. She is so bad she disrespects my mom punches the walls disrespects her teachers and principals cussed at them fights. She’s gotten suspended a bunch of times and almost expelled almost even kicked off the district. Cops have gone the times to talk to her and she does not listen. I wasn’t a bad kid at all always home until I turned 16 my mom let me go to parties she would even take me and I would drink smoke do drugs and ended up pregnant the guy left me n I wanted to abort but my mom didn’t let me. Once I turned 19 I changed my life ended up with a good guy I now have a8 month old my own place n in college. But anyways back to my sister so basically I want to help her so she won’t end up like me. My mom always calls me crying saying she don’t know what to do but she’s the one who still takes her places she gives her money. I never lived with my mom I lived with my grandma but my sister always lived with my mom and my mom would always let her go outside alone since she was like 5. We didn’t live in a good neighborhood either su that says A lot. My mom is a good mother I guess she does make sure they have what they need she doesn’t do drugs doesn’t beat them only thing is she lets us do whatever we want. My mom used to spank my sister when she was a toddler for “acting bad”. So now she says she doesn’t want to do that because she feels guilty. I’m like you doing have to do that just send her to jail it’s for her own good. Just earlier today my mom let her go to her friends house and a hour later she called my mom crying and paranoid to go pick her up. Supposedly they were driving (they’re all 13/14!!) and wrecked idk if they hit a car or a tree or what but it caught on fire. Her “friends”left her there got their own rides and she just got home my mom said and is acting like nothing happened now. My brother said My sister lost her phone there in the car that got caught on fire so my mom is letting her borrow her phone right now.. Im like OMG my mom is so annoying she’s over here calling me crying that she doesn’t know what to do n she still goes and gives her her phone WTF!!!!! Idk what to do I want to do something to help my sister she’s so young and my mom obviously won’t but I don’t want her going to cps supposedly kids in the foster system go through so much… any advice?