Greta is eleven years old and has gone two months without eating. Her heart rate and blood pressure show clear signs of starvation. She has stopped speaking to anyone but her parents and younger sister, Beata.
After years of depression, eating disorders, and anxiety attacks, she finally receives a medical diagnosis: Asperger’s syndrome, high-functioning autism, and OCD. She also suffers from selective mutism—which explains why she sometimes can’t speak to anyone outside her closest family. When she wants to tell a climate researcher that she plans a school strike on behalf of the environment, she speaks through her father.
Greta is not alone in her mental suffering, according to the book. Her sister Beata, who was 12 when the book was written, lives with ADHD, Asperger’s syndrome, and OCD. She is prone to sudden outbursts of anger, during which she screams obscenities at her mother.
https://quillette.com/2019/04/23/self-harm-versus-the-greater-good-greta-thunberg-and-child-activism/