From the same school of thought as, "Hey GM, which book did I just randomly pull from the shelf of the wizards' library?" No plot hooks here, just flavor additions.
Found, normally, deep in the swamp, the Friar's Weed's poison is something to be watched for.
Victorian Ladies used to use their decorative fans to communicate simple messages to their lovers while chaperones or husbands watched. These messages include "Yes", "No", "We've been discovered", "When can I meet you", etc. An Assassin's League of women could easily use this secret language to their advantage, sending messages to each other in hopes of reaching their target at a crowded ball.