She may have had the time of her life making the "Spy Kids" movies, but now star Alexa Vega, who played spy sister Carmen in the hit trilogy, said it’s time to put that character to bed.

Her first step away from the family film hits is "Sleepover," where Vega, now 15, is taking on the mission of dealing with mystery of high school popularity.

While the "Spy Kids" movies and "Sleepover" have two totally different vibes, Vega said the transition from a child role to a "tween" role wasn't that difficult.

"I think as you get older, I think your maturity level changes with you, with your roles," Vega told me in a recent @ The Movies interview. "When I was younger, I would have weirded-out by movies like 'Sleepover' because I hadn't had my first kiss yet and all that other stuff. So, I think, as you get older, you grow with the characters you play. With my character, Julie -- that was basically me about two years ago. I was dorky going into high school and scared out of my mind."

Vega stars as Julie, a 14-year-old girl who celebrates the last day of junior high with a sleepover with friends Hannah (Mika Boorem), Farrah (Scout Taylor-Compton) and Yancy (Kallie Flynn Childress).

But what's supposed to be an average sleepover party turns into a game with the "popular" girls of the high school, who through an all-night scavenger hunt vie for the best lunch spot for the next school year. The problem is, Julie's over-protective mom (Jane Lynch) has given strict orders for the girls not to leave the house.

While the movie has its fine share of hijinks, Vega said girls can learn from the movie, too.

"'Sleepover has great morals. You learn that shouldn't try so hard to impress other people and should just want to be yourself," Vega said. "There are so many problems with girls in high school. I even went through a stage in high school where I said, 'Maybe if I act like X, Y or Z I can be cooler. But you know what? Everyone goes through that phase, but you really don't have to. If you be yourself, people will like you so much better."

And the 22-year-old Farris, who joined Vega for the interview, said the popularity issue isn't just limited to girls.

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Preview: 'Sleepover'

"High school is high school, but it's not until you get out of high school that you realize that it's just a stepping stone in life," Faris said. "Nothing is easy about high school. I didn't know where I fit. There are so many cliques of people who are popular and who are not. You get too caught up trying to figure out where you fit in the whole scheme of things, but really, it truly doesn't matter. All that matters is that you have your friends who are your friends -- period."

On the lighter side of things, Vega got to show off her skateboarding prowess in the film -- in a scene where previously invisible Julie first catches Steve's eye.

Faris said the way his character reacted to Julie is the way he would have reacted in real life.

"Skateboard chicks are cool," Faris said, smiling. "They don't wear make-up. I like the whole natural thing."