Evolved

This is honestly my English assessment, I like it and want it online, idk if my teacher will say im plagiarising it.
Cassie is an eight year old girl who lived with her 17 year old brother and mum. One day, her brother hears about an evolving cyst in the brain making people violent and skeleton-like. He tries to keep her safe by taking her away to a safe place, but can he do it?