Sprocket,
You are right on the money. There isn't much hope for this child if this was an act without conscience, carried out deliberately and methodically. There is
no cure for a sociopath, because the problem is not a psychiatric disease, such as schizophrenia. Sociopathology, (now commonly referred to as Anti-Social Personality Disorder) is just that... a personality disorder. The severity of it does not increase, but rather the "patient" simply gets "better" (craftier, sneakier etc.) at whatever it is he (much less often female) "does", as a result of having the disorder. Therapy
rarely helps... and when it does, it is usually only because the "patient" is paranoid, and irrationally petrified of prison, or any lock down. Sometimes, they (sociopaths) do grow to be much more calm and less impulsive with maturity. This tends to make some believe they are "growing out of it"... especially girls.
Sprocket... I could tell you a ton of info about child sociopaths even though there is little about it on the web.
Mary Bell turned out to be a "somewhat normal" human being, with "somewhat normal" human emotional responses, when she grew to adulthood. She was released from custody at age 23. The vast majority of sociopaths (over 98%) do not show signs of improvement, but they are also men, and the hormone testosterone almost certainly plays a role.
Considering Mary's upbringing (before the murders of the two small boys)... and then adding in the terrible crime she admitted (to a point) to committing, one would have expected her to be destined to always be the ultimate "poster child" for making criminals
more dangerous by sending them to prison. But Mary Bell was never really sent to an actual penitentiary. As far as I know, she has still not committed another offense... and she successfully raised a daughter of her own without abuse.
Puberty played no role in the crimes of Mary Bell... if we believe she was the sole murderess and aggressor. (I still have doubts that Mary's friend Norma was simply an "observer" and "follower", as she was portrayed during the trial.) Mary was only ten years old, and then turned eleven during the time period when the crimes occurred. Some girls can begin puberty at this age, but Mary clearly had not.