Lady Wishfort demonstrates that, while you are only young once, you can be immature forever. Restoration comedy targets vanity in all its forms, and one of the most common of these is the refusal to grow old gracefully. Lady Wishfort retains the mannerisms and attitudes of a much younger woman, and by doing so she makes herself both ridiculous and vulnerable.
The dramatis personae of The Way of the World describes Lady Wishfort as "enemy to Mirabell, for having falsely pretended love to her." This shows another side to her character. As well as being vain and foolish, Lady Wishfort is vengeful. She is not depicted as innocent or in any way morally superior to the other scheming characters in the play; her malicious schemes are merely less successful than theirs.
When the audience first encounters Lady Wishfort in act 3, she is applying her cosmetics and showing clear signs of her various character defects, her vanity, her scheming nature, and her irritability. It is the last of these that is most immediately apparent, as she continually bullies her servant, Peg:
Ratafia, fool? No, fool. Not the ratafia, fool—grant me patience!—I mean the Spanish paper, idiot; complexion, darling. Paint, paint, paint, dost thou understand that, changeling, dangling thy hands like bobbins before thee? Why dost thou not stir, puppet? Thou wooden thing upon wires!
Lady Wishfort has been much discussed by the other characters in the previous two acts, but it is this first-hand evidence of her bad temper that quickly confirms her as an antagonist who the audience is glad to see thwarted and made ridiculous.