Role in the film Edit
Lady Tremaine is introduced in the prologue of the film. Young Cinderella's father, a widower, desperate for his daughter to have a mother figure, married Lady Tremaine, who is described as "a woman of good family", with two daughters, Anastasia and Drizella, of her own, and a cat named Lucifer. Lady Tremaine showed her true colors when Cinderella's father died, mistreating Cinderella while spending extravagantly on her biological daughters Anastasia and Drizella in hopes of molding them in her own image but also spoiling them as a result.
After the prologue, it is revealed that Cinderella has become a coerced servant in her own home and lives in a small room at the top of the tower in her house. An incident occurs in which Anastasia finds a mouse inside her teacup (Lucifer deliberately caused this to happen when he chased Gus). Lady Tremaine responds by piling a further order of chores on Cinderella as punishment, silencing her harshly (twice) when she attempts to object. She then, as a sense of poetic justice on Lucifer, adds onto the pile the request to give the cat a bath.
Lady Tremaine finally consents that Cinderella may attend the Royal Ball - that is, if she can finish all her chores and find a suitable dress. She then proceeds to heap chore after chore on Cinderella. Despite this, when Cinderella appears ready for the ball in a suitable dress (her mother's, altered to be more fashionable by her mice and bird friends), Lady Tremaine indirectly (but intentionally) points out that Cinderella is wearing Drizella's old beads and Anastasia's old sash that they threw away earlier in the day. This prompts Drizella and Anastasia to viciously tear Cinderella's dress apart, leaving her unable to attend the ball. When Cinderella, with the help of the Fairy Godmother, nevertheless attends the ball, her stepfamily does not recognize her. This was because of a combination of their belief that Cinderella was at home with her dress in tatters, the fact that Cinderella's new dress was in a different style from her old one and the fact she was made up so very differently to her usual appearance. Lady Tremaine does note a familiarity about her as she dances with Prince Charming close to her. She is not, however, permitted to study Cinderella long enough to make the connection, as the Grand Duke closes the curtains to give them privacy.
At the news that the Prince will marry the girl whose foot fits in the glass slipper left behind at the Ball, Cinderella becomes quite distracted and falls into a dreamlike state, dancing and singing "So This is Love" to herself. Lady Tremaine realizes that Cinderella was the mysterious girl who danced with the Prince at the Ball. She quietly follows Cinderella up the tower and locks her in her room, putting the key in her pocket.
As the Grand Duke then arrives with the glass slipper, Lady Tremaine instructs her daughters not to fail her. She watches as both Anastasia and Drizella try their hardest to force their enormous feet into the slipper. While this is happening (the stepsisters prolong the process with their repeated attempts to get the slipper to fit their feet), Cinderella's two mice friends, Jaq and Gus, steal the key from Lady Tremaine's pocket and bring it to the door of Cinderella's room. The mice succeed in freeing Cinderella from her room despite Lucifer's delaying them. When Cinderella appears and calls to the Duke, Lady Tremaine insists to the Duke that Cinderella may not have attended the ball as she has been a household servant, despite having deduced that she has. The Duke orders Lady Tremaine to step aside. Tremaine, however, remains determined to preclude her stepdaughter from trying the slipper on; she trips the Footman as he walks over to Cinderella, causing the slipper to fall off its cushion and shatter into pieces. Cinderella then reveals that she has the other slipper, and her stepmother watches in horror when it fits her foot.
See also Lady Tremaine on Disney Wiki