Curley's wife was bound to start trouble by getting into an affair with one of the men. There are always new workers coming along because there is such a big turnover in itinerant far labor. So if the men in Steinbeck's story all avoided her, there was sure to be a newcomer who didn't. In fact, it seems likely that she is flirting with the aim of trying to escape the ranch. And she is not the type of girl who could keep secrets. More likely, she would get into an argument with Curley and brag about her conquests among the employees. Curley is such a jealous, violent man that he could end up killing his wife and killing any man with whom she had been committing adultery. The men in Steinbeck's story are quite right in regarding her as very dangerous, not only because she is promiscuous but because she is immature and indiscreet. There is a possibility that she might run off with one of the workers, but these men have nothing to offer her and cannot be bringing a woman to the ranches which are their only source of subsistence--especially if the woman is somebody else's wife. Isolated as she is on this ranch, she is extremely unlikely to encounter a man who had a car and a good income and wanted to have any kind of semi-legitimate permanent relationship with her. If she did get away from Curley, she seems very likely to end up with the kind of man who would turn her into a prostitute.
I agree with #4 in that she would look to leave with any of the travelling workers who responds with a promise for the future and a response to her flirtation. I imagine she would not really attain any more happiness by doing this, but as others have said she is limited in experience and opportunity.
If Curley's wife would have the opportunity, she probably would run off with someone else, just as she has done in the past. Lonely and unhappy in her marriage with Curley, whom she has grown to dislike because he does not allow her to talk to anybody, she would again perceive flight as the only solution to escaping her discontent.
In the time and place where she lives, Curley's wife has very little chance for a good life now that she has married Curley.
In those times, husbands had a lot more control over their wives than men do now. A man like Curley who was also very influential in his area would have even more power because few would question his actions. This means that Curley's wife would have spent the rest of her life under Curley's thumb. She would have basically had to live her life in the way that he wanted her to. We can infer that this would not have been a very pleasant life because we know that he is very jealous of her and not very inclined to trust her. I imagine that he would eventually have become abusive of her the way he abuses other people who are weaker than he is. She would not have had any way to get out of that situation.
In the novel Of Mice and Men, by John Steinbeck, the character of Curley's wife (known only by that description, and without a name) is a woman who actually has a certain depth of character, which is only known to us shortly before she gets accidentally killed by Lennie.
From that slight allusion to her inner person, we get enough information as to know that Curley's wife is no different than the rest of the field hands in the story: She seems to have a dream that also crashed at some point and left her with no other option but to marry Lennie.
In her own words:
'coulda been in the movies an' had nice clothes- all them nice clothes like they wear. An I coulda sat in them big hotels an; had pitchers took of me. When they had them previews I coulda went to them, an' spoke in the radio, an'it wouldn'ta cost a cent because I was in the pitcher. An' all them nice clothes like they wear. Because this guy says I was a natural.
It is shortly after this confession that we realize that Curley's wife also wishes for a better life. Now, if this guy that said to her that she is a "natural" had actually fulfulled the promises he made her of fame and fortune, one could almost predict that Curley's wife would have made it as some sort of show girl, or lower-end entertainer. She may be pretty, but she has very little education, and no class. She only knows what she knows of life from what Lennie has shown her in the farm. She is completely limited by her circumstances.
Therefore, although Curley's wife can boast of having good looks, her intellect and life experiences limit her possibilities for a better life in a big way.