RS & BBM
A lot of us on here have our own stories of being a troubled teen and the factors that influenced those behaviors, but many of us can also say that our behaviors weren't a direct result of neglect or abuse in the home. I was one of those nightmare teenagers, yet I come from a wonderful family and had an enviable childhood. My parents had rules and expectations and my friends' parents didn't, so I was in trouble a lot. Unless one of Sherri's family members indicates otherwise, we really can't assume that her home life was the reason for her choices; then again, there's an equal chance that it was a factor.
Kids are still removed and placed in Foster Care for PINS and JD behaviors, and if there aren't any underlying abuse or neglect issues in the home, there's no reason to remove siblings, too. I work in child welfare, and I frequently see kids come into care who start off with problems at school and that escalates into behaviors that result in contact with law enforcement, eventually leading up to placement as a JD, but the family has never had involvement with CPS before. Placement as a PINS or JD is somewhat punitive, but it's primarily so the child can be more closely supervised while receiving whatever treatment or services they need to address their behaviors, or even to ensure they attend school if they are habitually truant. Back then, JD placements were definitely more punitive in nature, so it's entirely possible that Sherri was "sentenced" to a period of time in detention.
The answer to your question as to what "everything" is may refer to the events that led up to Sherri being removed from the home -- once Sherri got in trouble involving law enforcement, it started the ball rolling with juvenile court involvement and possibly probation and then placement. I don't doubt that dealing with her running away and having the school calling added unneeded stress to her parents' marriage, and if their split wasn't amicable then maybe tension in the home influenced Sherri's choices, but I would think that they were two separate events unraveling at the same time.
This is all MOO.