This takes place 8 months sorta after the beginning of the apocalypse. Lucille died 3 months give or take before they find Amelia. Negan is talking to both Frankie and Tanya in a romantic sense but he hasn't started his whole multiple wives thing. I like to imagine they meet when Negan is still in his peak of the loss and trying his hardest to lose himself in running the sanctuary. It's still newly starting so there aren't nearly as many people, and he hasn't started with such harsh punishments. Amelia starts off with little to no background but I'm going to add flash back chapters to give context about her.