Part of Lady Susan's vitality comes from her refreshing attitudes. She makes fun of conventional education for young ladies: mastering foreign languages and sciences is '..throwing time away; to be mistress of French, Italian, German, music, singing, drawing etc., will gain a woman some applause, but will not add one lover to her list. Grace and manner after all are of the greatest importance...'. Claiming that it pays to be eloquent rather than truthful, she says people will believe her own versions of events rather than Frederica's true ones: 'I trust I shall be able to make my story as good as hers. If I am vain of anything, it is my eloquence. Consideration and esteem as surely follow command of language, as admiration waits on beauty.' Like such flippant comments in Jane Austen's private correspondence, these assertions are not deliberately callous. They simply use a little comic exaggeration to underline life's ironies.
Lady Susan is not even so very wicked. Villain she may be, but she has impish humour – humour of the kind we admire in Elizabeth Bennet and in Jane Austen's own letters. When she says she 'could have poisoned' someone, we know she is joking. Apart from the coldness towards her daughter, most of her bad behaviour amounts to nothing more than telling people flattering lies.
She upsets the Manwaring family by seducing the husband and attracting Sir James Martin away from Manwaring's sister. Then she foists herself for the winter upon the family of her brother-in-law, the banker Mr. Vernon, at their country house, Churchill. She leaves Frederica a virtual prisoner at a boarding school. Lady Susan behaves outrageously with Mrs. Vernon's brother, Reginald de Courcy. Though he is twelve years her junior, she inveigles him into proposing marriage. She succeeds even though Reginald is suspicious of her, having been told about her behaviour with the Manwarings. Though she thinks little of Reginald, Lady Susan relishes her victory: 'There is an exquisite pleasure in subduing an insolent spirit, in making a person pre-determined to dislike, acknowledge one's superiority.' She wonders whether she ought to marry him and torment him for ever.
The terrified Frederica, ordered by her mother to marry Sir James, attempts to escape from boarding school and is expelled as a punishment. She joins her hostile mother in the country and so becomes acquainted with Reginald.
Frederica's letters to her aunt, she says, are not worth reproducing, as they were censored by her mother. So we are told briefly that Mrs. Vernon cared for Frederica in the country. Lady Susan in town married the 'contemptibly weak' Sir James Martin. With time, Reginald was to get over his love for Lady Susan and marry her daughter instead.
To Alicia, Lady Susan candidly describes her schemes to manipulate men and deceive women. She writes with such vitality and pride that she has the reader on her side.