My parents also went through divorce when I was 12, but idk why I already knew it was benefical to both of them, because if you can't live with a person, there's not just stress and tension on those 2 persons, but on the whole household, and by household I mean mainly children of those 2 persons, so maybe you can tell her that? And tell her it doesn't mean any of them love her less because of that, it's just that they stopped loving each other, and don't lie about everything will be okay, but the sooner she deals with it, it's better for her health, aswell as mental health.