The other piece I don't understand is why the parents went rushing home. As though Sydney going home from college was an extreme emergency. Above all, why mom would rush home when dad had been assured by Sydney that all was well at university, and Sydney was just wanting to take a break. Dad answered that quite reasonably by suggesting they could talk about it and maybe take a break for the summer. This is far from being an emergency, unless there was prior behavior that turned it into one. And I don't for a moment believe Sydney was threatening to harm herself. Barring that, they couldn't take care of it at the end of the day, after work?
Also, Sydney has startlingly little in the way of accomplishments: no intellectual talent, no AP's, average sports (not a college athlete), no volunteer work, no leadership, babysitting at games as her only work history, no musical talent, no artistic skill... There's no meat on that resume! Getting a 3.5 grade average in a non-competitive high school is nothing special: you get grade conscious (her teacher described Sydney this way) and do your homework. That's it! Even the teacher had almost nothing to say in terms of talent or special features. It's not a compliment to describe a student as "grade conscious" or "works hard": you say that when you don't have anything else to say that's specific and illuminating. It's not brilliant, bright, curious, creative, dogged, imaginative, innovative, inventive, forward thinking, mature..... And the teacher couldn't remember anything specific except the panic attack and the ski lessons?
Frankly, it makes no sense to me that Sydney had a scholarship to university, though maybe there was some hinky backstory to that, too?
I'm betting there's some serious pathology here, and the parents had a whiff of it, and were in denial or thought they could head it off. Even all the malingering for 3 years is OUT there. The defense psychologists didn't seem to bring themselves to recognizing it; I'll bet they'd never seen a version that extreme. Note: in her mugshot her hair is neat and tidy, no matter she's in a straight jacket. So much for the malingering crazy bird's nest mess she concocted for trial....