In the Tommy and Tuppence short story The Unbreakable Alibi, Majory Leicester is the flatmate of Una Drake at their flat at 180 Clarges Street. Majory told Tuppence that Una was definitely in London that Tuesday. Majory had not seen her that night as she had gone to bed early. Una came home about one in the morning. Majory saw her at about nine or ten in the morning on Wednesday.
Marjory Leicester is a character in LWT's 1983 adaptation of the story (Episode 7 of Agatha Christie's Partners in Crime) but she does not appear onscreen and is not cast. Tuppence does go to see her but this scene is not depicted. She reports the results of the meeting to Tommy. In this adaptation, Tuppence looks her up a second time but she encounters Una Drake instead. Una tells Tuppence that Majory has moved out.