That, at the moment is the million dollar swali - Im hoping they do the film justice and not miss too much out, Breaking Dawn has zaidi itimacy between Bella and Edward and the birth of their daughter too, it's going to depend on how much of that they onyesha bearing in mind even in the book nothing is really mentioned in detail about their nights following the marriage. The birth scene may be a bit to explicit if they go kwa how the book describes the whole event. Lets hope the producer (a good one we hope) will keep in time with the book but allow the younger audiences to appreciate it too - lets face it most younger members have read the book.
Honestly, I can't even imagine them doing a 'Breaking Dawn' movie. :I If it is PG13, I think that they'll have to censor some of the scenes where Bella is giving birth to Renesmee. That would minus off the gore and the 'fun'. :/
I think it should be rated R. But if there was a Breaking Dawn movie, the producers would most probably make it into a PG13-rated movie to fit the audience, which consists mainly of teeny boopers. :p