Non-household family member keeps dying every day??

Every time I load the game, or if I go into CAS mode while in the game, I get the notification that the same family member keeps dying. (Cassandra Goth) She is not dead. She literally came over our house. However, this is affecting my Sims moodlet and causing his work performance to be low. Even if I wait the 2 days, I exit and save the game- when I go back in, she 'dies' again. Does anyone know how to fix this? It's making my game unplayable because my sims are always sad. I don't have any mods or CCs either.