She came to Los Angeles at 17 with no contacts and little training, but within a year, landed a plum role opposite Hugh Grant and Drew Barrymore. This month, Haley Bennett plays a singing teen terror in Music and Lyrics By, a movie about pop-music formulas and fakery (but she really sings the songs). She's guileless, perky, and uses giggles for punctuation, which sounds sickening, but is quite charming.

Bennett: Marilyn, get down; no!

Please say Marilyn is a dog.

Yes. She's a long-haired Chihuahua. She's supercute. I'll send you a picture. She looks just like Marilyn Monroe.

In your new movie, you're in a bikini about 90 percent of the time.

Oh, my gosh, I'm an 18-year-old girl, and I don't have a lot of self-confidence yet. I had to lose weight for the role. There was a point that I was passing out at the gym. I had to rework my diet to get enough carbs. But I did it healthy. It wasn't the Nicole Richie diet.

You play a vacuous pop tart. Did you base it on Lindsay or Britney?

[Giggles.] Um, I based it on an imaginary character. wanted to make her crazy and vicious.

So you're not crazy and vicious?

No... people say I'm pretty sweet.

Are you crazy ambitious?

I'm very ambitious.

Is it true you're obsessed with Jewel?

I'd love to perform with her. I haven't met her, but once I kissed her dressing room door.

Any other celebrity fixations the authorities should know about?

I'm pretty obsessed with Angelina Jolie.

Angelina is a great name for a Chihuahua — if Marilyn needs company.