Daisy Miller: Character Profiles

Mrs. Costello:  Mrs. Costello is Winterbourne's aunt; she is a widower with three sons who never seem to be around. She is quite "exclusive," as Daisy calls her, and she doesn't hesitate to pass judgment on Daisy and her family. She doesn't use the polite phrases that seem to burden Winterbourne occasionally, and can often speak bluntly, as in calling Daisy "common," or calling Giovanelli a "barber's block."
Eugenio:  Eugenio is a professional courier hired by the Miller family to help with travel arrangements. He is polite and formal, but the Miller family encourages him to show more familiarity, and people like Mrs. Costello notice and remark on this. Mrs. Miller seems to ask Eugenio to help with her ineffective parenting, but his half-hearted attempts seem only slightly more effective. Eugenio seems to disapprove of Daisy's behavior.
Mr. Giovanelli:  Giovanelli is an attractive young Roman man, and he seems to fit the description of what Mrs. Costello calls a "fortune hunter"-someone looking for a wealthy young woman or widow to marry for money, or to exploit for money. He possesses perfect manners and a glib tongue; he is able to assume a humble air in the presence of people like Winterbourne to avoid offense. Most surprisingly, he manages to ingratiate himself with Daisy to the point that they become inseparable. Daisy at times seems to be using the suggestion of an engagement with him-even perhaps within his hearing-as a way to tease or otherwise attempt to manipulate Winterbourne. He disappears during Daisy's illness, and he confesses to Winterbourne at her funeral that he knew he had no chance at marrying her.
Daisy Miller:  Daisy, the daughter of a wealthy American businessman from Schenectady, New York, travels around Europe with her mother, who has very little control over her, her young brother Randolph, and her courier, Eugenio. Daisy seems to be in control of the group. Winterbourne calls her strikingly pretty, and she dresses very well with the help of her absent father's extensive fortune. Most importantly, she seems to be either completely ignorant or completely uninterested in the social rules that seem to govern the actions of someone like Winterbourne, or his aunt. She doesn't seem bothered, for example, when Mrs. Walker and Winterbourne tell her that she shouldn't be walking around Rome with Giovanelli. She continues this behavior despite the obvious disapproval of others. She admits to being an American flirt, and in the end she decides that she must see the Colosseum at night, despite both the threat of malaria and the suggestion of illicit liaisons. She dies of malaria at the end of the story, after this visit to the Colosseum with Giovanelli and an encounter with Winterbourne. Daisy represents what would become a typical James character (Isabel Archer, Christopher Newman, Milly Theale, etc.), an American with wealth but who struggles to negotiate European culture.
Mrs. Miller:  Mrs. Miller, Daisy's mother, must deal with chronic illness and a daughter who does not seem interested in anyone else's wishes. Mrs. Miller has difficulty sleeping, and also has difficulty with her son Randolph. She is an ineffective parent who appeals to her courier to get her son to go to sleep. Winterbourne makes several references to her shocking ineffectiveness with Daisy. Mrs. Miller enjoys discussing her various illnesses with anyone who seems interested, and she makes frequent reference to Dr. Davis, a physician from Schenectady. She is married to a wealthy and absent American businessman, Mr. Miller, who remains behind in Schenectady while his wife and two children tour Europe. When her daughter becomes ill, Mrs. Miller seems to transform herself into an effective nurse, and this seems to change Winterbourne's opinion of her.
Randolph Miller:  Randolph is the younger brother of Daisy and precocious son of Mrs. Miller. He plays an important role early in the story by enabling Winterbourne to introduce himself to Daisy. Randolph approaches him for some sugar, and Winterbourne uses this brief conversation as a pretext to speak to Daisy. Winterbourne also uses Randolph to get Daisy's name. Randolph himself clearly dislikes Europe and wants to go home, but he finds enough to interest him that he is reluctant to go to bed at night. For some reason, early in the story, Eugenio's success at getting Randolph to fall asleep becomes the signal for both Daisy and Mrs. Miller to go to bed. Randolph plays no major role in the second half of the story, though he does appear and makes some impolite remarks about how large his rooms are in relation to Mrs. Walker's.
Mrs. Walker:  Mrs. Walker is a friend of Winterbourne's from Geneva who, like many others, stays in Rome during the winter. She does not appear in the story until the third section, and she becomes the hostess of the initial meeting between Daisy and Winterbourne in Rome. She does not approve of Daisy's meetings and public displays with Giovanelli, and she attempts to intervene but fails to stop the behavior. She literally turns her back on Daisy when she later leaves Mrs. Walker's party, and she tries to convince Winterbourne not to see Daisy again.
Frederick Winterbourne:  Winterbourne is the main character of the story. He is a single, educated, and genteel young American man who lives in Switzerland (mostly in Geneva). He mentions that he was educated in Geneva, and he seems to have both refined and conservative taste. At the same time, he also has a strong desire to pursue his "adventure" with Daisy Miller. As his aunt, Mrs. Costello, points out, a "gentleman" risks less from such an association. The implication is that Winterbourne can have a questionable love affair with a young woman and still be active in "society," the cultivated social circle that he moves about in while he travels around central Europe.
Winterbourne appears to fall in love with Daisy, and he spends much of the story pursuing her and trying to find out if she is innocent (unaware of the way that people will respond to her affair with Giovanelli) or completely immoral. He seems to vacillate between these two possibilities throughout the story. He acts quite boldly in Vevey with Daisy, even proposing a visit to a nearby castle alone together. Though Winterbourne tries to intervene later between Giovanelli and Daisy, he commits similar indiscretions with her in Vevey.