madkarma, my heart goes out to you. From what you describe, I would suspect drug or alcohol issues.
Have you suspected drug use before? Alcohol use? Of course, I have been so fooled in the past that that may be a moot point. How dumb I was
Could you take her to your family doctor to rule out other physical reasons why her eyes may be dilated? While there, request a COMPLETE drug screen without her knowing ahead of time.
I don't read anything you wrote that would indicate not letting her return home or live at your home. Was there a reason she wrecked the car? Could she simply have poor money management skills?
However, I absolutely would explore your concerns about drug/alcohol issues. But, if the drug screen comes back positive, you would have to explore how you feel about her living at home. In my experience, it's a living hell.
The fact that you sought to post here seems that in your Mama heart you suspect something is quite amiss.
I was so fooled. You seem to be willing to tackle this issue head on!
With compassion,
Peaceandgrace