Persuasion is my favorite novel, but the scene where Louisa cracks her head bothered me. You have two men who fought in the Napoleonic wars- and fought well, in a time where naval warfare was supremely bloody- and the only person who keeps it together is Anne? It seemed a bit Mary-Sueish, what with no one else thinking to go for a doctor or carry her into the house. Then I realized: PTSD.
Could also be attributed to the bystander effect. To use wikipedia's definition "the bystander effect is a social psychological phenomenon that refers to cases in which individuals do not offer any means of help to a victim when other people are present. The probability of help is inversely related to the number of bystanders. In other words, the greater the number of bystanders, the less likely it is that any one of them will help. Several variables help to explain why the bystander effect occurs. These variables include: ambiguity, cohesiveness and diffusion of responsibility."