I agree with historiaamator's post #9. Steinbeck needed a victim for his plot, which is essentially about how one man feels compelled to kill his best friend, thus ending their dream of owning their own farm. We can't help feeling somewhat sorry for the girl who is brutally murdered--but if we feel too sorry for her, then we won't feel sorry for Lennie or George at the end. Steinbeck seems to be walking a tightrope with his depiction of the girl (who is probably only 16 or 17). He deliberately makes her appear vicious when she verbally assaults Crooks in his room and suggests that she could have him lynched if she wanted to. But he makes her appear kind, naive, harmless and vulnerable when she is talking to Lennie in the barn. Steinbeck had another reason for not giving her a name: She is the only female in his cast of characters. The men need names for the reader to be able to tell them apart. The men's names are as simple as Steinbeck could make them--Crooks, Candy, Curley, Slim, George, Lennie. There is nothing so great about the men having such names.
I suggest that the men are all afraid of having any kind of personal relationship with Curley's wife because she is obviously very flirtatious and her husband is obviously jealous and violent. They avoid calling her by her first name because that would be a step toward a more friendly relationship. By referring to her as "Curley's wife" they are constantly reminding themselves and one another that she is married to Curley, the boss's son, and is not someone to be thought of in any other context. Chances are that every man on the ranch knows what her first name is but doesn't even dare to say it aloud. Curley always refers to her as "my wife" and is obviously reminding every man that that is what she is. If he were to refer to her by her first name, it would seem as if he were giving the men permission to do the same thing. But if any of them ever used her first name when speaking to Curley, that man might find himself out of a job.
I'd like to echo the sentiments of post #2 and agree that Curley's wife participates, as a character, in the theme of loneliness in Of Mice and Men. She is lonely, unhappily isolated, and seemingly powerless to change her situation.
I do not feel that she is an accidentally representative of a politically and socially 'weak femininity' in this story as some of the posts above suggest. There is evidence to support the idea that Curley's wife is intentionally representative of a population forced to thrive on dreams for spiritual sustenance.
Steinbeck's main focus is on the fraternity of men; and, there are many obstacles in the way of this uniting fraternity which restores meaning and pride to men. Curley's wife, who is simply a genitive of him, acts simply as an Eve, a temptress to disrupt this fraternity of the men. She is a negative force in this novella.
This is a work that is supposed to show how American society has abandoned and abused many types of people. Workers are abandoned (George, Lennie, etc), black people are abandoned (Crooks). And women are abandoned and abused. This is why Curley's wife doesn't get a name -- it is meant to symbolize the extent to which the society of the time devalued women and their lives.
Curley's wife does not have a name because she does not have her own identity. She is just Curley's wife. She has no real sense of purpose. She does not fit in with the ranch hands. She lives a lonely existence. She has no friends:
Curley's wife (as the boss's son's flirtatious wife, she is not identified by any other name) wanders around the ranch searching for some human contact.
All that Curley's wife has is a dream. She is really considered a nobody. She has always dreamed to be a somebody. Sadly, all she can do is dream. Because of the isolation she lives in, she has no chance of ever making something of herself:
...she is pathetically lonely and had once had dreams of being a movie star. Both she and Crooks crave company and 'someone to talk to.'
Sadly enough, she is so desperate for attention until she reaches out of Lennie. She is flirtatious because she desires to have a name and be someone with a worthwhile purpose. In the end, Lennie accidentally breaks her neck. He too was reaching out for attention. She dies without a name. She is nameless because no one cares to know who she really is. The ranch hands have their own lives and she does not fit in.
I think John Steinbeck didn't give her name because she was not to be empathized with,she was just for plot points and stir up up trouble. As previously mentioned, she is an Eve/Jezebel to taunt and seduce men into sin and dispurt the men. Also in most men's minds,she is propetry of Curley and they better not touch his propetry! She doesn't have much power in the minds of the law. Curley's wife not having a name also makes it easier for us to not weep on her sad death,in which he turns this sinful Jezebel into a pure,innocent Mary by changing his words. Chances are she was neither a Jezebel nor Mary,just a woman trying to figure it out.
Calling someone by their name can be a gesture of respect and a way of connecting with them. The lack of a name for Curly's wife may suggest her disconnection from the rest of the workers and the lack of respect they have for her, revealing one of the larger themes of the novel-the loneliness and disconnection evident in the lives of most of these characters.