I'd like to claim great insight on that particular point, but SM gives it to us on a silver platter in an interview:StellaBlueBella wrote:You know, I never thought about it like that before but, I think you are right on the money! It sorta explains why she is not only unwelcoming to Bella but also condisending to Edward about his falling in love with a human, belittling his choice/feelings.corona wrote: Bella is also human, which Rosalie is jealous of, and Edward wants to keep her human; the implication is that Edward loves Bella more than Rosalie loves Emmett since she made Carlisle turn him into a vampire.
http://www.twilightlexicon.com/?p=198
Rosalie also gives us a brief flash on that same point in SM's extra, Miscalculation:
http://www.stepheniemeyer.com/pdf/nm_ex ... lation.pdf
- But I couldn't finish the sentence, because I could see it in my head, a vision of my own. A vision of me. An unthinkable vision of my life if somehow Emmett ceased to be. I shuddered away from the horror of the idea.
No--there was no comparison. Bella was just a human. Edward didn't want her to be immortal, so it wasn't the same. Edward couldn't feel the same!
Q. How could Rosalie underestimate Edward’s feelings for Bella so badly? What made her think that Edward would just go back to normal once Bella was dead? Especially since he had been already completely miserable when the two were just separated. Is she really that unobservant? Or is there more to it?
A. Rosalie is an egocentric person. One of the side effects of being born more beautiful than anyone else. Though she has her good qualities—loyalty, determination, self-discipline, and a very strong bond to her adoptive family—these qualities are often overshadowed by her self-absorption. She prefers to see Edward’s fascination with Bella as a strange quirk—and a transitory one at that. Because to Rosalie, of course, the main love story going on here is hers and Emmett’s. How could anyone else feel the same? Especially about some plain-jane human girl who Edward doesn’t even want to make immortal?
Ah, we’re getting deep into Rosalie’s well of denial now! See, Rosalie wanted Emmett, so she forced an unwilling Carlisle to change him. It turns into true love, and Rosalie has the staring role in the happily-ever-after-romance.
And then Edward falls for a human, and he insists on keeping her human. (Of course it’s different, since Emmett was bleeding to death, but, still) Rosalie can take this one of two ways. One: Edward doesn’t love this girl all that much. Two: he loves her more than Rosalie ever loved Emmett. Which way do you think Rosalie would prefer to look at it?