Am I wrong to disown my younger sister?

I'm 22, my younger sister just turned 18 a little over a month ago. I'm happily married, a homeowner, and we're trying to have our first baby.

I've tried to give her chances to warm earn trust. 2 years ago we had her house sit for us while we went on vacation. We paid her VERY WELL, $300 for the whole week while being allowed full run of the house with food, extra spending money and access to our video games. We came home to the animals not fed, dishes overflowing, clothes and stuff everywhere and days old takeout food sitting on the floor of the guest bedroom. We were pissed.

A year later, we tried again. She seemed more mature and wanted another chance. This time we installed security cameras. (For other reasons) We told her our closet was off limits because it has firearms and sensitive documents in there as well as just general personal stuff. No need for her to be in there while she watches the house. We had an extra camera in there. Sure enough, not even 24 hours after we left, she's in there with a stranger we had never met and they were both pulling out all my clothes and trying them on.(Over their clothes) She stole some and left town. (We took care of it immediately and had someone else relieve her, but we were so disturbed and felt violated.)

She's now 18. She lives with our parents. She brought a homeless guy home and hid him in their basement for a week because they were dating. He has no job, no license, no car or anything. I met him, he was a jerk and a bum and was using her. Total ass. My parents found out and kicked him out. The other night they were at some other friend's house. She let him take my parent's car to go get food at 2am and he ended up getting into a high speed police chase. They had to use spikes on my parent's car and he still kept going so they had to ram him. The car is completely totaled and he's in jail. Luckily he was alone and no one else was with him.

She started smoking, drinking and vaping at 17 and does all those things at home despite my parents hating it. She got a tattoo the day she turned 18 and it's the worst tattoo I've ever seen. Horrible quality. I begged her not to go to the same artist to get it touched up, saying she'd regret it. I offered to pay for a DECENT artist to fix it for her. She cussed me out and wanted nothing to do with me. She insists she loves it, we all know she doesn't and won't admit it, but there's nothing we can do now so I gave it a rest.

She's cheated on every boyfriend she's had. My mom told me she has an STD but refuses to tell me which one, so I'm guessing it's a bad one. She steals money from my parents and just the other day took my moms car without permission (because her hobo boyfriend totaled the other one) and brought it back with a huge dent in the passenger door and insists it wasn't her fault.

My parents do nothing. My mother calls me crying about how awful my sister is, but when I try to give them advice or I get upset, my mother starts yelling at me saying I'm not her parent and it's not my job to tell them what to do about my sister. They baby her and never punish her out of fear that she'll try to kill herself. My sister has body image issues, depression and anxiety. I know this, and I keep telling my mom she needs to find ways to help raise my sister's self esteem and self image- not just keep enabling this bad toxic behavior by letting her run rampant. She needs a new wardrobe to help her confidence, she needs someone to fix her tattoo so she knows she's worth having a good one, she needs to be around people who respect her and don't use her for sex and money.

My sister won't listen to me and hates me, so I tell my parents these things hoping they'll take the advice. I'll admit I can be harsh and don't say things in the best way, so I don't talk to my sister so I don't hurt her. I keep my mouth shut and stay cordial. But I'm tired of her shit, and my parent's shit. I'm the one everyone calls to complain to and cry to, but no one actually wants to get better. I'm embarrassed to be her sister, and I'm disappointed in my parents for failing her so badly. I'm constantly being told it's not my place to say anything or do anything. I've tried to help, to talk, to get them all to therapy. Nothing. I'm tired and I just don't think I want a relationship with her. At this point she's just a person. My husband agrees and thinks we should just focus on us and forget about my family and their issues and I'm really starting to think that's the best option here. I don't ever want her meeting my children. I don't ever want her in my home again. If she decides one day that she wants to grow up and apologize for everything she's done (There's way more, I just don't need this post to be a novel) then maybe I'll consider it. But right now I can't.