I found it in Persuasion, and here's the quiz. If a poll were taken of Janeites who love Persuasion and who know the novel really well, and they were asked which other characters in the novel Anne Elliot would have been LEAST likely to have been influenced by, I feel safe in claiming that most such readers would name Mrs. Clay as one of the top three answers, with strong competition from Anne's father and her sister Mary - or if the three of them were Disney characters,we might call them Sneaky, Snobby, & Whiny. ;)
Therefore, I was delighted to catch Jane Austen in the act of playing a sublimely subversive trick on her heroine, Anne, and on her trusting readers who see through Anne's eyes, by parading an example right before our eyes of Anne unconsciously echoing Mrs. Clay in a way that is nontrivial, in fact it goes to the heart of the romance of the novel
Can you guess, or if you have the time, search for and find, the two passages in Persuasion which provide the basis for my seemingly absurd claim?
If no one provides the answer by Saturday morning, I will reveal it then!