Move over Matt and Ben. A newer newbie has written herself into a plum part in a critically acclaimed film. And talk about a modern-day Cinderella story...

Once upon a time, 13-year-old Nikki Reed was busy living out her misspent youth with a vengeance. Then, Daddy's ex-girlfriend — production designer Catherine Hardwicke — encouraged her to put her wild child experiences down on paper. Together, they co-wrote the script for Fox Searchlight's Thirteen. Hardwicke got behind the camera to direct, and though she'd never acted before, Reed landed a huge co-starring role.

Hollywood's prodigy du jour insists she never actually expected Thirteen to be made. "We wrote it so that we could improve my acting. Catherine was trying to expand the areas that I was interested in," Reed, now 15, tells TV Guide Online. "We were planning on just writing it, and then going through all the scenes together so that she could coach me on acting."

As it happens, Tracy — the character based on Reed's life — was cast with former Once and Again regular Evan Rachel Wood. Reed herself got to let loose in the role of Evie, a popular, "experienced" girl who schools Tracy in sex, drugs and crime. "I got to be totally wild and say whatever I wanted," she laughs. "And I was like, 'Hey, I'm in character.'"

Now, Reed's basking in her rave reviews, though some significant people in her life have yet to express their opinions. "Neither of my parents have really said anything to me about the film," she admits. "And I think the lack of comments [from them] is what got the movie made. If they had said something — or if they had asked me what is real and what is not — that would have made it a lot harder for me."

Though Reed's fairy tale has a seemingly happy ending, has she any regrets about baring her secrets to the world? "I didn't know [my story] was going to get out there," she says. "I think if I knew from the start that all of this was going to happen, and that I would be going on Last Call with Carson Daly talking about my life, then I wouldn't have done this at all, because it has been really difficult. I don't regret it, but I am so happy that I walked in blindfolded."