Curley's wife looks to hang out with any of the farm hands in the bunkhouse and then with the men in the stables where Crooks lives. She does this under the guise of looking for her husband, but in reality is a lonely girl who has no one to talk to.
Before ever meeting Curley's wife, Candy tells George and Lennie what type of girl she is. He says he saw her give Slim and Carlson "the eye" and then goes on to say, "Well, I think Curley's married . . . a tart." This idea is confirmed, at least to George, when she visits them in the bunkhouse asking about Curley. She looks around the bunkhouse before turning her attention to George and Lennie. After admitting that Curley isn't there, Curley's wife "smiled archly and twitched her body" before adding the multi-layered statement, "Nobody can't blame a person for lookin'."
Later on, she shows up in Crooks's stables looking for Curley. This time, Crooks has none of her flirtatiousness and tells her to leave and that "We don't want no trouble." However, Curley's wife reveals a bit about her loneliness she suffers from on the ranch. She says,"Think I'm gonna stay in that two-by-four house and listen how Curley's gonna lead with his left twict, and then bring in the ol' right cross?"
The next time the reader sees Curley's wife, she goes into the stables to sit with Lennie. It's here where she completely reveals how lonely her life has become. She talks about all the other opportunities she had to move up in the world before finally admitting, "I don' like Curley. He ain't a nice fella."
Unfortunately for Curley's wife, she comes off as the reason why George has to kill Lennie. But she's just as lonely as the rest. As the only female character in the book, she, like Crooks (the only black character), experiences a loneliness no other character knows.