At this point, seeing how we're almost 100 chapters into the story, and her previous life has only been brought up like three times total (apart from her knowing what games are, especially this specific one), I do wonder if the specifics about how she ended up here are still purposefully being obscured. Her trauma caused by that suicide, which is the only actual thing we know about her original life, was highly relevant after all - who knows, maybe the circumstances of her death are related to how she ended up in this place?