What is one point in "The Lady or the Tiger" where a character has to mature or move on from childhood to adulthood? Rite-of-passage?
An interesting question. I would say yes, there is. However, it happens behind the scenes, or off-stage, if you will. It falls between the moment when the princess burns with jealousy for the other girl, which is described here:
"It was one of the fairest and loveliest of the damsels of the court who had been selected as the reward of the accused youth, should he be proved innocent of the crime of aspiring to one so far above him; and the princess hated her." And the moment when she points out which door is which, described here:
"Her right arm lay on the cushioned parapet before her. She raised her hand, and made a slight, quick movement toward the right. No one but her lover saw her. Every eye but his was fixed on the man in the arena." If she's grown up and successfully passed this threshold, she is pointing to the lady. (If mature, she knows to trust her lover.) If she failed it, she's pointing to the tiger.