Sister won’t get a job

Ok, so here’s a little backstory. Growing up my parents were drug addicts and their household was very toxic so my younger sister was very clingy towards me. She has always said that she feels like I’m her mom and I love her to death but I feel like I never really got to live my own childhood because I was always taking care of her. When I turned 16, I got a job with the intentions of saving as much money as I could so I’d be able to move out when I turned 18. Well fast forward to me turning 18, I had a boyfriend and we decided to move into an apartment together. After about a month and a half, my dad brought my sister over and asked if she could stay with me because since I had been gone, she was getting depressed. She wouldn’t come out of her room and barely wanted to go to school. I said it was fine as long as it was only for her spring break from school. Well fast forward a month and a half later, our parents announce that they are getting a divorce. In the midst of all of this, I get stuck with my sister….once again. She was 14 at the time, and they never even fought for her. Well, she’s been with me since then. She’s 18 now and since our parents divorce she’s just not the same. She’s been hanging with the wrong crowd, all she wants to do is smoke weed and get drunk with her friends. Her boyfriend buys her THC carts and she’ll smoke all day. I’ve suggested she get a job so many times and she just says she will but I haven’t heard about her going to any job interview or even turning in any applications. It’s just getting tiring because she’s always expected me to be her parent. She expects me to pay for her things and give her money because that’s how it’s always been. She’s never helped with rent, groceries, bills, etc. My boyfriend says that I’m being too nice to her so I told her that if she didn’t find a job by the end of the month, she should move back in with our dad. She didn’t seem too concerned about it and said she’d find a job. Idk what to do anymore, I guess I’m just looking for advice on what you would do? What would you suggest I do with her? If you’ve all the way down here, thank you so much!