Mrs. Clay, an unattractive but personable woman, is a widow and the daughter of Mr. Shepherd, the Elliot family’s adviser and lawyer. She forms a friendship with Elizabeth Elliot (even though Mrs. Clay is of a much lower birth) and accompanies her and Sir Walter to Bath—much to the concern of Anne and Lady Russell, who fear that Mrs. Clay seeks to seduce and marry Sir Walter. Socioeconomic mobility is one of the key themes in Persuasion; characters like Captain Wentworth, for instance, are able to make their fortune and ascend from “obscur[ity]” to “distinction.” However, the text makes it clear which social climbing methods are acceptable and which are not. Captain Wentworth was able to climb the social ranks because he has a successful career as a naval captain. His is considered to be a respectable profession, justifying his newfound place in the social structure. Mrs. Clay, on the other hand, is conspiring to manipulate a family so that she can marry well above her station.

The reader sees very little of Mrs. Clay but what we do see is concerning. For example, Anne notes that Mrs. Clay makes an effort to conceal her improper conduct whenever she is in Anne’s more observant presence. She is also seen having a clandestine rendezvous with Mr. Elliot on the streets of Bath, whom Anne has already learned cannot be trusted. Furthermore, Mrs. Clay is considered "dangerous" because a marriage between Mrs. Clay and Sir Walter would make Mrs. Clay the new Lady Elliot. This would mean she takes precedence over both Elizabeth and Anne at family functions, and would allow her to oust Elizabeth from her position as first lady of Kellynch Hall. Through her negative representation of Mrs. Clay, Austen argues that social mobility is only acceptable when it is done through honorable means.