One of the factors that strongly indicates that Marlow and Kate will enjoy a happy and productive marriage is the way in which Kate has seen the best and worst of Marlow. Thanks to her disguise, she has seen him for who he really is, and therefore the superficiality of pretense has been stripped away from him. In the same way, Marlow, through discovering the true identity of the supposed servingmaid that he pursues, likewise is able to understand what Kate is like and the kind of lively character that she is. A key theme in this play is hypocrisy and how characters present one face to society and are completely different when they are not in the public gaze. This is something that Kate has managed to get past in her relationship with Marlow thanks to her disguise, and there is a sense in which they know each other far more as a result than other characters, such as Hastings and Constance. At the end of the play, the good wishes of Hardcastle perhaps should be the guide to the audience's suspicions of Kate and Marlow's future felicity:
And Mr. Marlow, if she makes as good a wife as she has a daughter, I don't believe you'll ever repent your bargain.
Kate, therefore, in stooping to conquer and finding herself a husband, gives herself the best possible chances of happiness, even though her method of gaining a husband involved deception. In spite of this, her essential goodness of character is something that makes her a worthy catch and somebody who will make Marlow happy.