[Emmett to Edward:] "Let me dance with my little sister. This could be my last chance to make her blush." (4.236)
Emmett refers to Bella's human ability to blush – one thing Edward always loved about her. Her new body will no longer be affected by her emotions.
[Bella:] In Jacob's eyes – by choosing Edward, I was choosing a fate that was worse than death, or at least, equivalent to it. (4.148)
Until Bella actually becomes a vampire, Jacob is convinced that her transformation will be like she died. What makes him change his mind?
[Jacob:] The bonds fell off my body the second I embraced my birthright. (11.29)
The moment Jacob acknowledges the innate leader in him, he becomes immune to Sam's power. Does this moment feel believable, or a bit too easy?
[Jacob:] I knew it wasn't my imagination that my need for her was stronger than ever. Why was that? Because she was dying? Or knowing that even if she didn't, still – best-case scenario – she'd be changing into something else that I wouldn't know or understand? (15.125)
Jacob seems to be more afraid of Bella changing than of Bella dying, because unlike dying, her transformation into a vampire is something he can't relate to.
[Edward to Jacob:] "No. Not human. But she hopes to see Charlie again, anyway." (15.173)
Bella believes that there's a way for her to still have a relationship with Charlie after she turns into a vampire. Is that an understandable wish or is she being selfish here?
[Leah to Jacob:] "I'm talking about being a genetic dead end, Jacob." (16.107)
Leah's transformation into a werewolf have changed her human body and has possibly thwarted her ability to bear children.
[Jacob:] "She's not dead," [Edward] growled. "She's going to be fine." I wasn't sure he was talking to me anymore. Turning away, leaving him with his dead, I walked slowly to the door. (18.93)
After Edward injects Bella with his venom and her heart stops, Jacob believes that she'd dead. He gives up fighting for her life before Edward does. Do you think that part of him is relieved that at least she's not going to be a vampire?
[Edward to Bella:] "It goes against the grain… letting you wrestle with lions. I was having anxiety attack the whole time." (21.147)
Although Bella is a vampire now, strong enough to wrestle with lions, Edward has trouble not thinking of her as the clumsy, fragile girl she used to be.
[Jacob to Bella:] Maybe it's not the look as much as… you are Bella. (22.64)
Jacob realizes that although Bella looks different, her personality and essence have remained the same.
[Bella:] It was a relief and revelation to discover how much of my essential core traits had come with me into this new body. (24.30)
Bella learns that although thirst and desire never fade, they're manageable with self-control and determination, which have always been part of her character.