The thing with some conflicts is that when you actually look at it from both angles, you can kind of see where both parties are coming from. Like, yeah, maybe Louise had to do what she had to do, or at the very least had reasonable reason to think that she did. But sometimes actions like that can come with emotional consequences, because the sister you love so much can be reasonably read to have stabbed you in the back over somebody that did something fucking terrible to you. And maybe you're just not going to want to be around that sister who did terrible things to you anymore who happens to be spending more time with that sister that you love (and who it could certainly feel like chose Murder Sister over you), or at least need some time to back up, and regroup, and emotionally recover from what happened in your life, something that maybe the others don't see the big deal about but matters a fuck of a lot to you.
Sometimes conflicts don't have a Good Guy and a Bad Guy, but it's just two individuals struggling with their own issues and have to make the choices that make the most sense to them, even if it means there's conflict and struggle and maybe at the end of the day somebody isn't entirely looking at the Big Picture, or Optimally Rationally, because that's not the way human beings operate and it'd be silly to carry that expectation into a work of fiction, really. And maybe that means relationships are changed forever, maybe that means somebody just has to... back a way for a while and re-evaluate and afterwards things might be not be the same as they once were but... good enough. Or everybody manages to patch things up. It all depends, and I think any of those resolutions can be completely fair and understandable when it comes to everyone involved. And you don't want every conflict to be like that really, but it's nice to have them sometimes because they're refreshing and human.
It's important to remember that in the story, characters are kind of people too, they exist within their own universe and within that confines aren't going to act like LogicBots or what might Make The Story A Certain Way, but how an individual might reasonably act in that situation, because they're individuals operating, within a simulacrum of reality.