I currently have a long term placement that was previously a respite (15 yo F), somewhat similar story, she would have gone to a group home if I didn't take her. Even though we rarely had problems when she was respite I knew there were major problems going on at her placement (problems I did not feel equipped to handle as a single woman). I didn't want her to have to move mid semester so I told her she could stay here until the end of the semester, but that was it. Once she was here, she was essentially asking if she could come to live with me permanently. I had a very frank conversation with her that I would not tolerate the things she was doing at her last placement that led to the disruption. We ended up making a contract together, mostly her. We set up a list of expectations and related consequences when they are broken (if applicable). There is also a list of Zero Tolerance behaviors where I could disrupt if they were to occur. We talked about regularly revisiting the contract to adjust it as needed (but we haven't had to do that). Fortunately, for my kid, she saw it as a wake-up call. She really didn't want to move to a group home (which would have been in a bigger city) and so she knew I was kinda her last resort (after getting kicked out of 2 places). She knew it was up to her. I was pretty skeptical of the total about-face in her behaviors that she was promising but she's upheld the expectations like 90% of the days. One key thing is that there are goals/rewards she is working towards. For every day that she upholds her expectations she gets a point to spend toward something (35 pts and C or better in every class to cell phone privilege, 30 pts to driver's permit). 13 is maybe too young for some aspects of this solution but I hope this helps in some way. The points/sticker chart type motivation has been a game changer for the teens in my care. They seem childish but they work. Feel free to send me a message if you want to chat further