pink hair is clearly mentally not fine, probably trauma or something, she puts up an act to get people to like her or feel below her so they can't question her actions, the hamster probably represents the brown haired older girl while the cat is the new girl, the abuse part the new girl mentioned about not taking care of cats is probably the fact that brown hair is using pink hair, putting her into 'abusive' or 'bad' situations so that she can stay with her, since her only dream of being an actor or director went down the toilet because of lack of talent, and she's mad pink hair has that talent, she's probably super evil, pink hair opening up and realizing she's lesbian is probably a way to show that she's moving on from the lie she has been projecting to others (like how she's fine) and instead embracing the truth (she's not fine but she's trying to be better)
ORRR the brown hair has been letting pink hair do thing her own way never telling her something was a bad idea, basically enabling her bad habits till they got this bad
(LET ME USE MY OWN PROFILE PICTURE! MB! LET ME UPLOAD MY OWN PFP!!!)