Board Thread:Character Discussion/@comment-13019683-20140512201937/@comment-32390199-20140522184223

Actually we don't know if she was killed in the original timeline. Maybe it always had to be that she was taken back to the present at that point. Similar to how Simon Petrikov created a time portal to say sorry to his fiancee Betty Grof who then jumped through the time portal to be with him in Adventure Time. Maybe it already was set in stone that Marian disappeared to the future.