This is likely above the 95th percentile writing skills for neurotypical twelve-year-olds, and uses anachronistic language to boot. When's the last time you heard a twelve-year-olds using words like "I am weary", or" for causing so much hardship.", or idiomatic abstracts like "another way of being".
If you took a neurotypical kid and duct-taped their mouth shut up to age 12, you would be robbing them of the vast majority of reinforcement learning on grammar and wording that we receive as children, and it would knock them down several standard deviations in skill level relative to their peers in constructing sentences, paragraphs, and essays.
On top of all this is the blatant wish-fulfillment. Socialized kids, at least, have a some degree of ego, and don't often express sincere thanks for their parents, their disorders, that their "school values them", or describe their behavior as "Then I would have meltdowns.". These are forced reflections that just don't occur naturally.
On top of all this is the core of autism: Deficits in the theory of mind. Normal kids start to master deception, pretending, prediction of behavior, and empathizing somewhere between 2 and 5, and get gradually better at it as they get older. Autistics have marked problems in these areas. What they don't do is clearly model their audience, model their audience's ignorance of their own mind, then tell their audience to walk a mile in their own shoes, and describe the novel aspects of their mind from the perspective of a neurotypical outsider. There are recursive layers of social intrigue in this paragraph that people with autism would have a great deal of trouble understanding, much less writing:
"Let’s pretend you are like me. You can’t talk, but you have a well-functioning mind and can understand people. Imagine you answer everyone who says something to you, but only you can hear it. Others hear your voice saying things you don’t necessarily mean. They think that’s all you are capable of thinking. People see your repetitive flapping or tapping and they think it serves no purpose. They don’t understand that the minute you stop, the moment is flooded with lights that hum, loud sounds that echo, kids moving too fast for you to keep up with and people trying to engage with you. It is hard on me to put my stimming away, but I try."