Well she's still a kid. Infact both of them are. If I were in her shoes i would've drowned myself in self pity too. Besides after their mom died Subin also kinda grew colder, too. Which i don't blame but she was also a kid. When ur one and only family, ur brother whom u used to rely on suddenly changes overnight u would start to recent them lil too. And again THEY WERE AND ARE BOTH CHILDREN.
I understand but also age cant excuse one from being an ungrateful and overall bad person. its fundamentally up to u to be empathetic to the people stuck in the same situation as u or wallow in self pity and develop this unhealthy outlook, especially considering her age
I hate the sister so much how little compassion and love can u have for ur brother who is working his life off tryna make things work. He coulda pawned u off to an orphanage but he still chose to take care of u and what do u do in return? Get into trouble bruh