Judy (Kim Novak)’s Timeline and Summary

Makes her entrance late in the film, as the last of several Madeleine-lookalikes.
Is followed home by Scottie and reluctantly agrees to go out with him.
Delivers a confession that triggers a flashback, revealing what really went down between Scottie and Madeleine.
Had pretended to be Madeleine when she was hired by Elster, who wanted a way to murder his wife without being caught.
Had taken advantage of Scottie's fear of heights, knowing that he wouldn't be able to reach the top of the bell-tower when Madeleine "jumped" off (really was been thrown off by Elster, who had already killed her).
Tears up the confession letter, deciding she wants to try to make Scottie love her for who she is, putting the past behind her.
Goes out with Scottie and agrees to his plan to give her a makeover and transform her into Madeleine.
Is reluctant at first, but then settles into a role that's familiar to her after all, since she's played Madeleine before.
In a thoughtless moment, puts on Carlotta's necklace, which Scottie recognizes.
Is taken by Scottie to the Mission at San Juan Bautista, where she is forced to confess to her deception.
Back in the bell-tower of the Mission, which Scottie forces her to climb, also declares her love, but only to hear Scottie say that it's "too late" for the two of them.
Jumps off the tower she'd climbed before as Madeleine, this time as herself.