How is George and Lennie's dream of owning their own place different from Curly's wife's dream?
To me, the real difference between the dream of the two men on the one hand, and the woman on the other, is that the men want to be independent while the woman wants to be famous. These are really fundamentally different things.
George and Lennie dream of going off by themselves and having a ranch. They dream of being their own bosses and doing things on their own schedule. By contrast, Curley's wife dreams of being a movie star. This is not something where she is being self-sufficient. Instead, it is a dream in which she becomes well-known and glamorous.
You can argue that this is one thing that makes Curley's wife a less sympathetic figure than the two men. Her dream is less attractive -- she does not really want to be her own person.
Similarly, George and Lennie are searching for something that would satisfy the soul from within. They long for a peace at the end of a workday wherein their efforts and the fruit of their labor benefits just their human needs of sustinence and fulfillment.
Curley's wife is longing for something which can never fulfill her in the long-term. Her dream is a facade of relationships. Acting or modeling are great careers for a time, but they don't last and they exist to serve others in a superficial way. I guess it would serve Curley's wife in a superficial way for a time too. The temporary life of luxury and glamour would feel good for awhile, but it won't last.