I think this girl is nearly 13-16 because she mentioned about the bullying things happened when she started secondary school. So she should be a teenager figure. And maybe I will keep the headphone with her to emphasis the different between whether she is with her music or not.
And about the characteristic, I think she is a brave girl and won’t give in. She is strong and fight with the bad mood but sometimes can’t defense it. Even was dragged into the panic and stressful situation but she will stand up and keep fighting.