Everybody has a dream they wish would come true, whether it's a wide-eyed boy staring into space, a teenager getting onstage at an open-mic night or a jaded adult clutching a lottery ticket in one hand and a note of resignation in the other. For the characters in "Aquamarine," the discovery of a mermaid inspires the most sincere of friendships, simultaneously fulfilling two childhood wishes.

In real life, actresses Emma Roberts ("Unfabulous") and Sara Paxton ("Sleepover") have seen many of their dreams made real. And although she's no slouch in the entertainment business, Joanna "JoJo" Levesque is discovering that her newest friendships are helping to support her latest fantasy: that of becoming a movie star.

"This is my first [movie] interview!" the barely-15-year-old shrieked recently as she discussed her film debut with MTV News. "I'm glad the two other girls are here, because we kind of feed off each other. And that makes it a lot less painful."

Although she's been acting and singing for years, JoJo has been careful in preparing her transition to film, beginning with this month's family-targeted mermaid flick and carrying into April's road comedy "R.V." With her mother standing nearby and Roberts, 15, and Paxton, 17, busily chatting her up before the cameras were turned on, JoJo undoubtedly felt right at home.

  JoJo, Emma and Sara At The Premiere Of "Aquamarine"
 "Aquamarine" Photos
"Aquamarine" Trailer
  Check out everyting we have on "Aquamarine."
"I've actually been acting since I was 6, doing professional theater and stuff like that in my hometown of Massachusetts," she explained, brimming with the self-confidence that has already helped her become a recording star. "So acting wasn't a new thing for me. But as far as film, it was new, and these girls are so professional and everybody was so great to work with. It was a first-time director. So we were learning things about each other and learning the ways of this film and the process."

Coming in for an assist to her younger, first-time co-star, the elder Paxton chimed in with an attempted breakdown of the flick: "The basic plot is two 12-year-old girls who are best friends, they ..."

The golden-haired screen mermaid stopped herself short. "Wait a minute. Are you guys 12?"

Looking back at her, Roberts and JoJo shrugged their shoulders and giggled.

"Well, OK, two girls, age unknown," Paxton grinned. "They are best friends and they find a mermaid in their swimming pool. ... They feel like outcasts. And my character comes along, and she's not from this world — she's from underwater, literally — and she brings confidence to them."

In real life, the stars insist, there are no such things as mermaids — just actresses in really tight outfits. "She looked really good in it," Roberts promised, soliciting a "Thank you, Emma" from Paxton.

"The first time I actually wore the tail, it was really weird, 'cause the tail's like 100 pounds or something, really heavy," Paxton reported. "So, five guys on a stretcher had to carry me everywhere. When I was in the full outfit for the first time and they brought me out on the stretcher, I felt like a princess. Everyone was clapping for me, and I raised a hand in the air and everyone's like 'Whoo hoo!' and then they threw me in the pool like a fish."

"Aquamarine."

Visit Movies on MTV.com for more from Hollywood, including news, interviews, trailers and more.

.