Much of this behavior could also be attributed to her being raised in a sheltered, privileged environment where kids aren't held accountable and have little interaction with those outside their social class. To some, arrests and prison are things that happen to poor people, not them.
She does seem erratic, possibly depressed, but should be capable of understanding the consequences of her actions. Kids spend enough time on the internet and social media these days to be informed about the real world, what happens to "other people" who help plan murders. But their upbringing and environment make them think they're "better" than others and not subject to the same rules and laws. Affluenza.
Hopefully, the court will appoint some professional, objective experts to provide a psych evaluation instead of relying on the expert opinion of her attorneys and personal health care providers.
