Mrs Gardiner and Charlotte indiscreet in relation to significant news items. Is Charlotte so intimate on a conversational basis with Mr Collins she might speak of Lizzy's confidence? Surely if nothing else, Charlotte would also be fearful of the reaction of Lady C if she found out- as the Collinses and Lizzy are cousins- so would keep her mouth shut accordingly? Still, Lizzy stayed with them at Hunsford those weeks and must have seen their domestic relationship. And she does not end up informing Charlotte.