ksm, this is so worrying for you. I know how you feel, I've been there many times. As an adult, she can refuse treatment unless she is deemed to be a "danger to herself or others". And that determination of her being a danger to herself is subjective according to the local mental health unit and police.
It's good she seems to be coming around a little bit but it's clear she really needs help. From what you have mentioned she is paranoid and has marked delusional thinking.
Most likely from what you've mentioned she doesn't have any substances at the moment, but considering meth and opioids showed up on blood tests only a week ago it's kind of strange she's not desperately trying to get out to get something. Maybe that's the reason she's trying to get in contact with the boyfriend so much and can't think of any other way right now. I'd keep a very close eye on her for any outside contact for now if I were you regardless of anything else.
At your place she will not be doing drugs and she has the safety net of support from trauma that may have triggered possible underlying mental illness. This is very good for the short term but most likely will only help in turning her life around but not steer the ship to any degree.
I'm hoping regardless of what she is sharing with you that she knows she's not thinking right and she will come around and decide she needs mental health help.
