Tell her to gather her things and come with me. She’ll be cleaned up, put into school and I’d go through the legal proceedings to adopt her.
If she’s too old to adopt then I’d get her a job or into university. She could stay in my living room and I wouldn’t charge her rent until she gets on her feet. Most young women in that situation are on that bag so if she won’t put it down then she’ll go into a rehab program.
Even though I step over the homeless most days I still have a lot of compassion for them. I’ve been there. I know how bad it can get. Most people just need to be shown a little compassion and given an opportunity to become better.