Lady Susan Vernon is the titular character of Jane Austen's Lady Susan. She operates as the book's main antagonist, as she is an adulteress, is cold, and cruel towards her daughter. Lady Susan has one daughter, Frederica Vernon, whom she does not like and makes no attempt to hide the fact. She represents immorality in the novel.
Since she is styled as "Lady Susan", she is the daughter of either a duke, marquess, or an earl. She was most likely brought up in luxurious circumstances, and likely made her come-out at the palace when she was around 16 to 18. She made a society marriage by wedding a wealthy and distinguished gentleman, although he was untitled.
She had one child with her husband, Frederica Vernon, with whom she shared little in terms of personality and general traits. This made Lady Susan dislike her daughter. Her husband became ill with a terminal malady, and was sick for a very long time before his death, which was Lady Susan's excuse for why she did not connect with her daughter.
Lady Susan fancied several affairs after her husband died, and was encouraged by her dear friend, Alicia Johnson. Mrs. Johnson prodded her to ignore Frederica and to focus on herself. Reginald De Courcy and Mr. Manwaring were the two main contenders, however, Mr. De Courcy was unwed and heir to a large fortune, while Manwaring had a wife already.
Lady Susan's physical appearance is described as being very beautiful, as she looks like she must be 25, with a lovely complexion, and fine grey eyes framed by dark eyelashes.
Susan is excellent at dissembling, which may come from being raised as a member of the aristocracy, as she has a very gentle demeanor when speaking to new acquaintances that disguises her true feelings for them. This is seen in Catherine Vernon's account of meeting Lady Susan, even though she knew that the other lady despised her for marrying Charles Vernon.