Jane dies and finds herself still in the world, but unable to interact with it, or be seen by anyone. Around her are the 107 billion other people who have also died throughout human history.
How would ghosts find ways to oppress and abuse each other? They have no money, strength, physical appearance (or do they?) so what would they base their hate on? Century of origin? Age when deceased? Whatever it is, I’m sure they would find some creative way to separate themselves into groups, then beat up on/take advantage of the smaller groups.
It’s human nature, dead or alive.