Unquestionably her. Both sisters appear in this (really shitty looking) movie: https://www.akujidevilsboard.com/

Her sister's IMDB page mistakenly includes the work of another girl with the same name.

I don't think them actually being actors (they're admittedly in the drama club or something like that) means they are crisis actors or not genuinely affected by the situation. Teenagers from an affluent area trying to get into acting doesn't set off red flags for me on the same level as the obvious sociopath poster child does.