Forget Kate Middleton's wedding gown.
How about being chosen to design Bella' Swan's dress for her walk down the aisle?
"I worked on that dress for like six months going back and forth," Herrera said. "I still have all the sketches and everything because it was so special."
But she is nervous.
"There's so much expectations," said Herrera, who has designed real-life wedding dresses for starlets like Christina Hendricks, Renée Zellweger and most recently Amy Smart. "I hope [the fans] like it."
Herrera didn't have to research too much to come up with the right look. "It was a combination of things," she explained. "I got inspiration from the book and descriptions from Stephenie Meyer. You had to really take in consideration the whole story—which was this innocent girl with the first true love of her life. It had to be magical."
The fourth installment of the Twilight movie franchise hits close to the fashionista's home. "I have four daughters and 12 grandchildren," Herrera smiled. "They are all waiting for the movie."