County Family Services?

Have police bust her on drug charges...
or
Have her arrested on theft charges...
refuse to accept her into the house if they try to offer probation?

Search her room for any drugs, make it obvious that you've done so (leave it a mess).
Do it again tomorrow.
And the next day, until she decides to change or move out...

If she is 17.5, you have only 6 months before all charges become "permanent, adult" charges.

I feel for you. I also have a 17.5 yo stepdaughter, and a 15 yo and a 13yo plus my own 15 and 13 yo. Good luck.