Although Jane addresses Alistair as "Uncle", he is actually her "great-uncle-in-law", as her mother is his niece by marriage.
Jane is tall and thin, and her face has an "intelligence and aliveness" that redeems its "lack of actual beauty". She is dark, and has deeply tanned skin. Her voice is "warm and deep, with a trace of American accent".
Jane meets Japp and Poirot as they are leaving the Gothic House, Alistair Blunt's house in Chelsea. She asks if anything has happened to him, and when told that they are investigating the suicide of Henry Morley, she says that it is absurd.
Jane later asks Poirot to come to the Gothic House. She tells him about an incident in which Alistair had met Mabelle Sainsbury Seale at 58, Queen Charlotte Street. Miss Sainsbury Seale had claimed to have been a great friend of his wife's, and had asked for a subscription to Zenana Mission.
Jane tells Poirot that she loves Howard Raikes, and that her mother had brought her to England partly to get her away from him. She had asked Howard to make the appointment in Queen Charlotte Street so that he could meet Alistair, and see what a "nice kindly unassuming person" he was, hoping that Howard's hatred of him would diminish. However, after making this arrangement, she was worried that Howard might have tried to harm Alistair.
Jane later tells Poirot that Howard wants her to marry him at once, without letting anyone know. She asks him what she should do about it, saying that she cannot ask her mother for advice as she would "scream the house down", Alistair would be "cautious and prosy", and she does not have any friends.