I don't care for the mother because of the behavior she has displayed in court. However, I do not agree that we can come to the conclusion (with info currently available) that her parents did not try to help Jodi.
It is VERY DIFFICULT to get help for a child over the age of 18. You cannot FORCE them to do anything, and in fact, your hands are tied in dealing with the doctors, counselors, etc due to privacy issues. They can't even tell you what is going on because of HIPPA laws (that is if you are lucky enough to get them to agree to see someone!).
They may have tried to get JA to get help, spoken to her friends, etc but JA would have most certainly resisted. With a family member who displays far more "disturbing" behavior than JA did (prior to the murder) I can tell you that once they are 18 you are pretty much screwed. It is their life and if they choose to live it in a mental health altered world you cannot stop them. Having tried SEVERAL times to get this relative committed as a harm to himself or others it is NEARLY IMPOSSIBLE! Even though he posted on FB a photo of him with a gun to his head and stated he was "done living", the hospital would not keep him overnight. It is unbelievably hard, heartbreaking and frustrating to love someone who doesn't love themselves enough to get help.
Instead, they continue to do more and more dangerous, stupid or illegal things and they end up in jail over and over again. It is a vicious painful cycle, often more for the ones who love them than the person themselves.