Did they ever say exactly how she died? I mean, in the episode where we find about her life, she says the robbers killed her younger siblings, however her narration left me with the impression that they left her alive. So, how'd she end up there?
Yuri said herself that it wasn't suicide, because that's what Otonashi thought. Yurippe's death is never explained or revealed, but it definitely wasn't suicide. If you committed suicide, you wouldn't have ended up in that particular part of the afterlife. It's explained in the episode where they go to the guild for the first time.
Otanashi never had to even open his mouth...Yuri was flustered right aaway and shouted that it wasn't suicide, looked like a defense mechanism to me...
I personally believe that she was killed by the robbers later on in her life, after she tried to attack them. I think what's been shown about her fight in the afterlife implies that she wouldn't rest until she got justice for her siblings, no matter how much she blamed herself for it. In fact, the way Yuri blames herself makes me feel like she tried to do something about it, and it failed. That makes me think that she tried to hurt the robbers and got killed in the process
I personally believe that she was killed by the robbers later on in her life, after she tried to attack them. I think what's been shown about her fight in the afterlife implies that she wouldn't rest until she got justice for her siblings, no matter how much she blamed herself for it. In fact, the way Yuri blames herself makes me feel like she tried to do something about it, and it failed. That makes me think that she tried to hurt the robbers and got killed in the process.
^ This. I also think she felt like her friends in the Battlefront were people she was supposed to protect too, and by helping them she was somehow slowly making up for the deaths of her siblings.