Nancy is a Hungarian patient overcoming an allergy to potatoes, being treated at Ernst Stavro Blofeld's allergy-research institute high up in the Swiss Alps and a henchwoman in On Her Majesty's Secret Service. She was played by actress Catherine Von Schell, credited 'Catherina' in the credits for the film.
Nancy first appears when Bond, posing as genealogist Sir Hilary Bray, visits Blofeld's allergy research institute high in the Swiss Alps of Piz Gloria. Although all the women at the institute take a liking to Bond, he becomes the center of fascination from both Nancy and Ruby Bartlett. While becoming acquainted with Bond as Hilary, Nancy makes it clear that she like many of the other girls share a dislike for Blofeld's second in command Irma Bunt.
Continuing their discussion at a dinner table, Nancy is curious to know Bond's (still posing as Hilary) background, especially his job as a genealogist. During conversation Nancy tells Bond that she is overcoming an allergy of potatoes at the clinic, but as she now adores them, it's all she eats. Flirting continues between the two at the table and Nancy takes a keen interest in a book Bond is claiming to have brought with him to the clinic which include pictures.
- James Bond: "Now, when we authorize a coat of arms, it can include all sorts of funny things. Crescent moons, portcullises, beasts couchant and rampant, bars, bezants..."
- Nancy: "Please, what is bezant?"
- James Bond: "Gold Balls."
- ―Bond posing as knowledgeable Sir Hilary Bray.
Bond arrives from seducing Ruby to find that Nancy has broken into his room, disobeying Irma Bunt's orders of patients and visitors remaining in their own rooms once lights are out. Still intrigued by the book with pictures Nancy is surprised when Bond would rather spend intimate time with her believing him not to be interested in girls due to him posing as Sir Hilary. Bond and Nancy kiss as they fall on the bed, implying the two have sex.
- James Bond: "I don't even know your name"
- Nancy: "I tell you all about myself later. In the morning."
- ―As Bond and Nancy fall on the bed.
The following morning while playing curling with her fellow patients Nancy continues to flirt with Bond, planning another time to meet up in the evening. However, that evening, Bond is tricked by Irma Bunt when visiting Ruby before Nancy, captured and sent to Blofeld for interrogation. During the investigation, Blofeld reveals he is brainwashing the patients so that they distribute bacteriological warfare agents throughout various parts of the world.
While Bond is captured the women are given leaving Christmas presents from Blofeld himself. The presents in fact include an atomizer which intended purpose is to spread the bacteria upon Blofeld's orders and a communicating radio. Nancy leaves the clinic with the rest of the girls, but after Bond destroys the facility and warns M about the attack planted in the minds of the women, Blofeld's plan is inactive. The future of Nancy, is unknown.
- Although friendly to Bond, Nancy, like all the other women currently being cured at the clinic are essentially henchmen for Ernst Stavro Blofeld and potentially a strong enemy to Bond and the rest of the world depending on the status of Blofeld's plan and agenda.
- Nancy appears in the novel On Her Majesty's Secret Service suffering the same allergy of potatoes, however her character name is Violet.
- Nancy is often not credited as a primary Bond girl due to the similar presence of Ruby Bartlett. However, Nancy is considered a henchmen but still illustrates all the main conventions of the 'Bond Girl' and becomes intimate with him. The potential reason for her being unrecognized as a Bond Girl (only Tracy Bond and Ruby Bartlett being mentioned) is due to Ruby's strong presence in the novel. This being said, On Her Majesty's Secret Service features three prominent Bond Girls with Nancy acting as one of them.
- Nancy is a unique character, in that she's technically a villain/henchwoman, but not knowingly. Unlike most women in her position, who either change sides or are forced into their villainy.