In the novel A Murder is Announced, Julia Simmons is the sister of Patrick, and a cousin of Letitia Blacklock. She and her brother are staying at Little Paddocks. Although they are cousins of Miss Blacklock, they affectionately refer to her as Aunt Letty. She is training as a dispenser at Milchester General Hospital.
Julia is good-looking, with chestnut hair, and very attractive hazel eyes. She is usually cool and aloof, and often adopts a bored expression.
In the BBC 1985 adaptation of the novel which formed part of the Miss Marple series, Julia Simmons (or, in reality Emma Stamfordis) is played by Samantha Bond. The portrayal here is very faithful to the original. She is also an ex-member of the French resistance.
In the ITV 2005 adaptation of the novel, Julia Simmons is played by Sienna Guillory. Miss Blacklock later found her passport which showed that her real identity was Emma Masefield. Her father was Alex Fabricant which was the name of the husband of Sonia Goedler in this adaptation. Sonia and Alex Fabricant later split up and the twins Pip and Emma were split up as well. Like in the novel, Emma went with her father. Fabricant later changed his name to Masefield. Like in the novel, Emma took on the identity of Julia Simmons when living at Little Paddocks. The only difference from the novel is that the real Julia is not training to be an actress in Perth. Here she is living with a man to whom she is not married.