I realise on re-read actually, that you mention autism, rather than aspergers? I have met people with the later (who are just people who dont relate emotions socially it would seem, or experience much emotion at all, from my recollection), but not the former. There are probably lots of elements beyond my understanding here, and it must be hard....
In fact its hard to imagine the combination. Person I knew with aspergers was very non-emotional. I guess maybe there are different presentations.
But I guess the question is, really at the core, what would the real benefit of guardianship be? Would it help her get better care, or better treatment? Would is actually acheive that better treatment (keeping in mind that mental compliance in treatment is more important than legal permission). Would their be disadvantages to it, is there anyway she could suffer because of losing control?
Shes living with you, shes getting therapy, shes taking drugs. I am not sure how happy or not she is about all that, or how forfilled she is, or where her emotions are at, what her level of functioning is, if theres an emotional dimension to her symptoms, or a brain structural abdomality - perhaps thats detail beyond this discussion and u dont really say - but is there some critical thing thats shes not doing?
She wanted to avoid incarceration, and a loss of violition, thats quite natural. But you wanted her to get some kind of help with her emotions and her actions is it? Thing is, you cant really force a process like that. It might be more helpful if you encourage some course of action?
And worth remembering, no matter how bad someone symptoms are, a person does need more than protection. I still cannot imagine being in the psych system from age 8 or 10. And shes 19 and living at home, which even if your emotionally stunted must wear a darn little thin at times. Does she ever feel she has independance or liberty? (And could she manage a tiny smidgen?) Could she do an at home study course? Even if shes not well, I hope she has some kind of sense of hope going, some desire for something good.
It still strikes me this talk of suicide, violence and escapism (drinking). There's some heavy emotional current to all this right here. People arent random, even mentally ill people, even if they seem that way to others...