What is the most suitable title: "She Stoops to Conquer" or "The Mistake of the Night"?
Well, in my personal opinion "She Stoops to Conquer" is a much more artistic and clever title for this play. "The Mistake of the Night" is okay-but which mistake? Marlowe's belief that Constance is a barmaid? Mrs. Hardcastle's lie doubt the missing jewels? The fact that they turn out to truly be missing?
The term stoops is great-it means to lower something or someone. Constance lowers herself to the position of a working class woman to test Marlowe's feelings for her. Marlowe is uptight around women of the higher classes and is not himself. But working women were subjected to the sexual advances of men, and more often able to see their true nature. Constance stoops to find the real Marlowe.
Constance also stoops to deception. She chooses to play a role to sneak a peek into Marlowe's real nature. It is a risky choice, because if the relationship works out, she has started it with a lie. It could have backfired on her, as well. Marlowe could have been incensed that she put one over on him, and never talked to her again.
But, in the end, "She Stoops to Conquer" is the right title, because by lowering her status, she finds out that the real Marlowe is someone she can love.