White Rain, I understand that it can be hard for parents to get help for truly dysfunctional, mentally ill, and/or physically dangerous teens,.
But I have to be honest and say that I think most of what your own SD did was very normal acting out and a desperate plea for help and attention = /sneaking out of the house/ smoking pot/ sex/foul mouthed back talk/ tattoos/ dramatic writings/ piercings/ lying to stay out of jail. None of it is certainly anything a parents wants for their child, but none of it is abnormal either. And it also doesn't mean that she's a bad kid or that her future will be bleak.
For several years your husband only raised his daughter on weekends, so a few 24 hour nights at the hospital, the stress of raising an unhappy and defiant teenager, and some extra cash for a few special programs/parole doesn't seem all that awful to me, especially when it seems she was in this position because of decisions the adults in her life had made over her entire life time.
It wasn't acceptable behavior, but it was still within the normal range of teenage behavior, things that could have and should have been handled in a much less dramatic fashion and in a much more compassionate way. The multiple sex partners is worrisome because it points towards the need for a more involved father figure or possible sexual abuse having been perpetrated against her at some time. The un-named misdemeanors are also concerning, but I'm sure you don't really want her locked up in prison, right? She needs/needed fellowship, counseling, group therapy, a mentor, etc. And I do agree with your that those should have been offered to her and the rest of your family, by the schools, churches, her doctors, the courts. This is a problem, a nationwide problem, one that needs to be addressed and dealt with.
Nothing she was doing was really all that terrible. These things would be terribly worrisome, imho: prostituting and/or stealing for hard-core drugs, not using protection and getting pregnant, or an STD or AIDS, dropping out of high school to runaway and move in with her unemployed boyfriend, plotting the murder of your family or strangers (and not just on paper or in her mind), telling huge, life altering lies such as telling the cops that your husband was molesting her so she could get out of going to jail or the mental hospital lock down. Tattoos, pot and sneaking out to meet a boyfriend just don't compare.
Some day you need to step into her shoes with all your heart and soul for a few moments:
You have parents who were apparently incapable of raising you for whatever reason, a reason that it not your fault but still makes you feel like you're not good enough.
You've been rejected by your own mother, the one person in the world who is supposed to be there for you unconditionally.
You've never really had an average day to day life with your father.
You're being raised by your grandparent and then you are rejected by her - so now that's two maternal failures.
You've been kicked out of your home, you are scared to go into a new situation, "taken in" (how generous!) by the father who had previously been unable to raise you full time.
Living with a step-mother who doesn't seem to like you much and appears to see you as as your father's problem, which feels like a 3rd maternal rejection.
You have a new sibling and this happily excites you, but this child WILL be raised with the parents you should have had, and with the home life you should have had.
You feel a bit envious of the baby, and oh so lonely, misunderstood, unfairly treated it and picked on.
Nothing you do seems right or good enough.
You're still such a young lady, but you've been through more emotional troubles than most adults ever experience.
And no one has ever taught you or demonstated the tools you need to properly cope with your confused and angry emotions.
In the case of the murders of Calyx and Beau, I think the opposite problem was occurring. It was the mother, their murderer, who had a problem/s that weren't being adequately dealt with. The family chose mostly to ignore her escalating problems, including her anger issues, alcohol abuse and depression. They never returned to Al-Anon; CPS didn't take seriously the many complaints of abuse made by Calyx. The father was not involved enough or in tune enough to know deep the problems with his wife ran. This mother didn't murder her children because they were uncontrollable delinquents who caused endless trouble and continuously disrespected her by being 'mouthy'. She killed them because she was in an alcohol fueled rage, unable to properly react to typical child behaviors.