I think the honeymoon was a good way to introduce an important reason why Bella should change, because afterwards, it would save her life. It made Bella and Edward's relationship stronger. This is not only because of love, but because it gives them the most challenging obstacle they've ever faced.
I've found with Stephanie Meyer's writing that she likes to give everyone a happy ending. This was a hard one to find a possible way to make a happy ending, and even though its a bit of a stretch, she managed to make it work. The critical side of me is not at all crazy about the last books in the series, but she gave people what they wanted. Bella and Edward could be together forever, and Bella didn't have to give up the human experience of raising a child. And not even Jacob was left behind in the dust -- he ends up with a soulmate. So I think that's why she chose to write the final book that way, to create a happy ending.
As for the honeymoon scene, people have argued that it's not appropriate for young readers because of the sexual activity. However, I can think of many books that are much worse in terms of explicit content. Twilight is very chaste in comparison, and Bella and Edward were married. I don't know if it is appropriate for some of the very young readers of Twilight (I've seen third graders reading these books) but for most of the teen (and adult) audience out there, its perfectly appropriate.
I think Stephanie Meyer was trying to wrap the final book up too fast. I actually think the final book should have been two seperate books. Meyer seemed to race through the honeymoon chapter too fast. I would have liked to see her develop the plot a little bit more. I agree with the first responder though. She came up with a good plot twist in having Bella pregnant.
This chapter definitely showed how much Bella had changed and she went from her normal self to her protective mother self. WIthin this period she also showcased how she grew and was in more control. What I liked though is that they showed Edward and Bella to wait until after marriage to actually sleep together unlike how some people in high school don't wait.
I think the honey moon chapter was a good way to show just how much Bella has changed, even if a little, from being regular Bella to a protective mother Bella. This really showed Bella in a new type of light which was really nice. And we can see with Edward just how much he has grown control wise.
Me, as a high schooler, after reading the series a few times feel that I put my morals higher on my list of things to keep. It showed me how special your honeymoon can really be and I'm excited to have that happen to me one day when I find the right guy. Having the social preassure we have now-a-days to just grow up faster then we need to, that casual sex is everyday life, and being a virgin is for losers and nerds is horrible and i'm glad we have atleast 1 book series for my age that promotes waiting untill marriage.
I think that the author couldn't have found a more convincing way to cause Bella to change. Though she wanted to in the entire series, this was the most convincing way it could have happened, nothing else would have been satisfactory. The author made a critical decision there. What did you think?