Losses [UC]

Losses.. There was someone who lost her best friend. She was depressed so much, that she never cared about anyone but herself and did not connect with nature, You are a detective, the girl's brother asks you if you can figure out what changer her. Watch out, as the girl lived in a town full of menaces. Well, atleast you can deal with them. (For any 8-11 year olds, there is only one jumpscare)