Need Sisterly Advice, Please

Asalamu alaikum sister, I’m carrying something heavy and would appreciate some Islamic guidance. I’m 29 and my sister is 39 with two kids - one is 18 and the other is 2. She’s never been steady in life, always moving around. When she had her first child she gave her away and that child suffered abuse and a lot of trauma. I was a child then and helpless. Lately my sister’s situation got worse and she was close to being homeless. Alhamdulillah I recently bought a house, and because I didn’t want my nephew to suffer, I invited them to stay. She said it would be for three months and that she’d start a new job within a month. But she stayed home and gave excuse after excuse, didn’t pay bills or buy groceries for two months, and expected me to cook for everyone. She even got upset when I prioritized feeding my nephew. After I pushed she finally took a job but still hasn’t contributed financially. I’m exhausted and I want peace. For background, my sister has always been unstable: jumping jobs, getting evicted, never staying more than a year in one place. She once told me she feels like someone did black magic on her and that she has no willpower. Growing up she also refused to clean; she’d hide dirty dishes instead of washing them. It’s been the same here - she won’t tidy up after herself or her son. My mother and I have to keep reminding her, and once she even insulted my mom when asked to clean. She also smokes weed and the house smells of it. I’m a practicing Muslim and I don’t want that in my home. At first she smoked in the bathroom and lied when I confronted her. Now she goes outside but leaves her little boy alone. He’s wandered off six times and only by Allah’s mercy were strangers able to bring him back. She doesn’t properly wash or feed him even though there is food in the house. I feel so guilty for that child. I’m at the point where I want my sister to leave because I need my space and peace, but I feel deeply guilty about the nephew. I worry how Allah will question me on the Day of Qiyamah if I turn them away. Please advise what I should do in this situation - how can I balance my duty to help with protecting my household and faith?