What Compassion has said SOUNDS RIGHT TO ME!
Set up boundaries and limits.
However, since she is 16, I'm not sure what the law says regarding your rights and it would be wise for you to know. Do you have a legal representative you can double check with?
If drugs are involved, you can also ask about the Marchman Act. This will mandate her to get drug treatment and it might be a la the gov't....free of charge. It will literally force her to go.
Yes, I would consider striping her room down to the basics and provide her with essentials. Determine the necessities like food, shelter, clothing, education, doctor's visits and medication.
I would NOT give her an allowance with the POSSIBLE exception of a small allowance IF AND ONLY IF she does something very much needed and very much defined in the home. If it is not done or done in a half.... way, then DON'T reward her with money.
All of this will be up to you. Super duper hard to enforce, but my guess, super duper important that it IS enforced.
I would make certain things a requirement to live in the home: no drugs, no breaking the law, a reasonable curfew, no cursing or threatening, school or GED preparation class followed by the test.
Do this in a calm manner. If she can't abide by the rules, you can suggest that she find another place of residence. You might consider writing this all up in a form of a contract and have her sign it. Tell her that you would like her to live in the house....which comes with not only the necessities of life, but certain "extras," like maybe cell phone, computer and TV. TEll her, if she can't abide by the rules and choses to act inappropriately, then she choses to break the deal.
As appropriate...PLEASE take her to see the doctor and see if she might need medication and/or birth control if you have not done so already. Consider taking her to a therapist (but only if she is willing to go, etc.)
I would help with medical issues and necessities of life if she is at your home.
Try to get your emotions out of this...I do think it is likely to be of some help.
Love the idea of YOU getting support from FA, NAMI and the like.