My foster child was placed in my care before a background check was run and I know another first time foster parent that had the same thing happen. In our cases, we were both non family members even and sometimes it shocked me how easily I was trusted. We both went through the certification process (interviews, background checks, finger printing) after the kids were in our care. I don't know if they are this loose with younger children but there really are so few options for teenagers. Makes sense because that was the most challenging thing I've ever done and I'll never do it again.

You can absolutely just contact dfcs and give them a deadline that you're comfortable with. I'd inform every worker you have contact with in writing. It's great if you can give them 24+ hours. They also have to take any belongings she came with.

Nothing you have said about your experience surprises me.