Shifting sands

My eldest is, we suspect, well and truly on the Spectrum.
But this is tantamount to an insult as far as she is concerned.
With her poor social skills and inability to recognise body language/behaviour around her all her brother's life she has considered him as spoilt.

No matter how much we explained the Spectrum to her, no matter how often we walked her through the meltdowns, the screaming, the causes and what triggers to avoid - throughout it all she still thinks he is merely spoilt.
She doesn't see that she behaves in almost identical fashion at times, she doesn't like it when I treat her as she demands her brother be treated - straight forward and with boundaries firmly marked.
She falls to pieces, often, not understanding those around her, not stable in relationships on shifting sands, not trusting friends or boyfriends due to her inability to read situations and others' behaviour but blaming everyone else in her obtuseness.
She is a clever cookie, she has been tested and found to have a high IQ and she could have blitzed Uni or further studies if she'd chosen.
But we knew, deep down, that she was too flighty, too unsettled in school, too distracted by those around her and too bored with subjects she either found too easy or had missed some relevant part and so the rest was gobbledegook to her.
She just pushed and pushed until we were called to the office to hear that not only had she not submitted any homework or projects for the entire year 11 but, at 6 weeks left of the school year, she was more than likely to fail unless she knuckled down immediately and got the missing work done, with much help offered by her teachers, and she could scrape through.
She refused.
She demanded to leave school.
She couldn't cope with the social interactions from other students, she couldn't distinguish between learning and social times, she threw herself wholeheartedly into projects only to get used and burned by others for her efforts.
And now she's employed in work that earns a good rate but she has no title, to certificate, no goal to acheive or race to run.
Just drifting on her shifting sands.