On the set of Breaking Dawn, Kristen Stewart is eager to embrace the next exciting chapter of Bella and Edward’s love story. In the new issue of OK!, on sale this week, we take a look at what’s new in the Twilight Saga movies. The difficult birth of Bella Swan and Edward Cullen’s child is one of the most terrifying scenes in the whole Twilight series, and Kristen can’t wait to film it! “Bella does change a lot,” Kristen, 20, says. “She [becomes] such a mother. I think it will be awesome to see how much she’s changed from Twilight, where she’s a 17-year-old kid who doesn’t really care a whole lot, to see her become this matriarch.”

OK! GALLERY: ROBERT PATTINSON & KRISTEN STEWART KISS KISS FOR BREAKING DAWN NEWLYWED SCENE

But Bella’s new maturity occurs only after she goes through the agony of delivering her half-human, half-vampire daughter, with the aid of Edward (Robert Pattinson). And the early word on the script of Breaking Dawn, which will be released as two movies, is that Renesmee’s birth will be every bit as shocking on screen as it is described in Stephenie Meyer’s novel.

OK! NEWS: A VERY FEATHERY BREAKING DAWN — FIRST MOVIE STILL ARRIVES!

In this week’s OK!, Kristen and Rob talk candidly about filming Bella’s pregnancy. Will the movie’s depiction remain close to the book? Plus, a collector’s edition yearbook as OK! looks back at how much has changed since the Twilight phenomenon began! And whichTwilight hotties are still single?

ALSO IN THE NEW ISSUE OF OK!:

The Royals: A Royal Update! As Kate Middleton prepares for her April wedding to Prince William, an exclusive first look at her dream wedding dress. Plus, the world’s top fashion designers give the inside scoop on Kate’s style and how they would envision her dress.

OK! GALLERY: PRINCE WILLIAM & KATE MIDDLETON CELEBRATE ENGAGEMENT; SHOW OFF PRINCESS DI’S RING

Real Life: Accused murderer Amanda Knox’s life behind bars as OK! talks to her former cellmate. What is life like for Amanda behind bars? And who will play Foxy Knoxy in the upcoming movie?

Melissa Rycroft: Only in OK!: The Bachelor star’s baby shower as she awaits the birth of her little girl with husband Tye Strickland. Find out which former Bachelor stars were a part of the festivities.

The Big Debate: Should Prince Charles step aside for his son, William, to become king? Was Miley Cyrus‘ 18th birthday party too provocative? Is MTV to blame for Amber Portwood losing her child? The experts weigh in.