I think my friend might be possessed?

I need help! I'm really scared for my best friend. I don't know if she really is possessed or maybe just is under so much stress she might be going insane. It started when her mom and her sister got into a big fight and she defended her sister... After that her mom threatened to disown her and her dad already disowned her about a year ago (her mom and her dad are divorced). For awhile I know she's had really no friends and animals are unusually attracted to her. And then when she actually did make a friend they don't seem close anymore like she left her for her other friends and then her other best friend died. I know she promised him before he died that she would always protect her other friend no matter what since her friend and he were dating. After that shes been acting strangely. She isn't happy or cheerful anymore somedays when she goes to school her eyes would just be completely empty and it's scary and somedays shed go to school and just be unusually happy and I can't tell if she's faking it. Sometimes when she would invite me over strange things would happen, sometimes she would just get up in the middle of the night and leave the room. Id follow her but she would just seem to disappear out of thin air. There was also a time when she asked me if I would wait in her room and I would see her go to her backyard from the window and a crow would land in front of her. She'd kneel down and just stare at the crow and it would stare back as if it was telling her something. Also the stray cats near her house always seem to follow her and are constantly around her when she goes outside, same with all the crows. They'd just land next to her when she sits down. One time when I was sleeping over she suddenly just started screaming and holding her head then she would just suddenly stop, when i'd ask her what's wrong she would just smile and say 'nothing's wrong.' Then another time in the middle of the night she started clinging to me and she was shaking like she was scared or something. She told me she heard something in her head like it was calling her then she would just stop shaking and she would go back to her own bed without a word. She also told me lately she's been scared she can't keep her promise anymore. I'm really worried about her does anyone know what could be wrong?