My aunt is in that situation. She is severely mentally ill and homeless. She was in a shelter until a few months ago, no one has heard from her since. No one else in the family can afford to get her treatment, and she wouldn't comply even if we tried - she doesn't know she's mentally ill, she thinks her delusions are reality. We would all be relieved if she landed in jail as long as it came with some treatment. She is very intelligent, though, and she is not using drugs or alcohol, so she may never get herself in enough trouble to land in jail.
Committing people to treatment against their will sounds like a bad idea just begging for abuse, but what else can we do? In what world could she actually be taken care of? I don't know the answer.
Involuntary commitment is the reality for many people. Sometimes the delusions recede enough that they recognize they are ill.
I would encourage you to look for a support group for family members. Sometimes it helps to know other people are struggling with the same issues, and see how they cope with those issues when there's not a solution.
Committing people to treatment against their will sounds like a bad idea just begging for abuse, but what else can we do? In what world could she actually be taken care of? I don't know the answer.