Whether she tried or not, she can only do so much to begin with. Stopping them before was a fluke. And even if she could go back again in time now, there's still nothing she can do to stop this from happening (even if she went to authorities). She'd just look like some crazy girl spouting about the imminent death of her adoptive parents. I think it's so ridiculous to put so much responsibility over her just because she knows they'll die. She may be older than her body but she's still just a child. And knowing that they 'will' versus the exact 'how' is just another factor to be taken into consideration. So peeved whenever I see comments saying, "why didn't the MC do anything'.