I actually also came here looking for exactly this question.
Sadly, with discord's "dox yourselves" ID requirement shenanigans, I've deleted my account. (Sorry, any argument with a through-line of "think of the children" is never actually about the children-- I won't truck with it, and this one is especially egregious by way of making children even more vulnerable online than ever before. But that's a tangent for a different time and place.)
Is it possible to get an adequately spoiler warning laden answer to the question here? I doubt I'm the only person in this position, and if they're willing to go as far as tracking down this post, I would be more surprised if they're worried about spoilers than not.
I'd like to clarify here, I've found 4 endings to Amei's story. I even loaded a much earlier save and made attempts to intervene during the riots, thinking it may be a case similar to the church story where you must meet a specific character first to get the happy ending, or act to uncover Melissa's nature quickly enough, but no joy (no immediately obvious change in story).
Mostly, I'd just like to know if I'm wasting my time?
I can only think of 2 instances where you have the option to choose reactions with her, but it's entirely possible that an earlier decision I've made has cut off the means to assist. For example, I've ignored the "join us" email and cut off that entire questline, I can't imagine the two are connected, but I can't be certain.