ET went behind the scenes of Ashley's photo shoot for Teen Prom magazine, where the actress dished about her rigorous fight and stunt training for 'Eclipse.'

"I was excited about the photo shoot. I wasn't too nervous, I've been in a prom dress before," said Ashley, looking glamorous in a strapless, floor-length purple gown.

"I'm trying to convince them to let me take the dress so I can go out in it," she giggled, "but I don't think it's going to happen."

Ashley, whose Teen Prom issue hits newsstands Dec. 22, also showed off a bruise on her arm (rendered practically invisible with makeup) that she sustained while training for the eagerly awaited third 'Twilight' film, 'Eclipse.'

"Until I had to shoot in prom dresses, I didn't get any bruises. I was doing really well," she smiled. "It's horrible, but it's been really fun. [Our moves] will look really, really good by the time we finally get to the fight sequence because in 'Eclipse' ... we have to fight this new-born vampire army."