@Nerdosaurus16 - you mentioned that she's enemies with Eliza Pancakes. Perhaps she goes after her and tries to make her life miserable?
In my game....I have an evil Sim, and it's a very long backstory but her enemy, she's made it her life's mission to make this Sim miserable. She's a Jungle explorer....and I love using the relics. I'm in search of the relic for 'marked for death'....but for now, the one she has makes people sick, etc. Forgot what it's called....but once the epidemic spreads to one person, if you hug or touch another person, that Sim gets infected. So far, there's tons of sick Sims in my worlds LOL.