In chapter four of Steinbeck's Of Mice and Men, Curley's wife does do all of the things the previous editor states. We also see more of her sympathetic side in the closing pages of the work when she talks to Lennie in the barn.
However, what she does to Crooks in chapter four reveals such a negative, manipulative, ignorant part of her character and her personality that it is difficult to feel any sympathy for her.
When Crooks stands up to her, she plays, figuratively speaking, the reverse race card. She threatens him with her ability to get Crooks, a black man, lynched by saying that he tried something sexual with her, a white woman.
She destroys his spirit and puts him back in his place, as both her, and society for that matter, see it.
This is a despicable example of what Curley's wife is like. It's hard to feel sympathy for her after this.