People: We’ll be seeing more of Demi

Demi Lovato, 15, bounces onstage at Six Flags America, microphone in hand.

“How are you guys doing tonight?” she asks her fans, who are mostly girls just a couple of years younger than her. They scream, cheer, wave their arms.

“Wow, you guys are a fun crowd, not gonna lie!” Lovato says.

Born Demetria Devonne Lovato in Dallas, she has a big voice and a bigger smile.

A pianist, guitarist and singer, she starred in Disney’s latest made-for-TV musical, “Camp Rock.” Her first album of self-written songs comes out next year.

Lovato got her start on “Barney & Friends,” singing and dancing with the purple dinosaur

“Some people might think this is an overnight thing, but really it’s been about eight years in the making,” she says.

Her popularity is due in part to the long-haired, guitar-slinging Jonas Brothers, her co-stars in “Camp Rock.” She’s opening for them on their 43-city Burning Up Tour, which launched July 4.

Lovato’s stepfather, Eddie De La Garza, quit his job as a Ford dealership manager to be her manager and travel with her.

“We said when this all started that we’d keep our family values, and that’s what we’re doing,” he says.

Dianna De La Garza, Lovato’s mother, is a former Dallas Cowboys cheerleader and country music singer.

“I think I would worry more about the fame if I didn’t know Demi’s level of maturity when it comes to doing what she loves to do,” she says.

A Christian, Lovato says a group prayer with her band before they perform. She sometimes wears on a chain around her neck a plain silver ring, inscribed with “True Love Waits.”

Her apparent maturity is born of experience in learning how to deal, as the kids say.

In middle school, Lovato says, “I went through a really hard time at school with girls bullying me. I blamed it on myself at the time, but looking back I guess it was out of jealousy.”

One day, upset and frustrated, she called her mother and said, “I want home school.” The next week, they were out buying materials.

“I’d gone through so much rejection at that point with girls at school that I couldn’t do acting anymore, where all I was doing was working hard and hearing ‘no,’ ” Lovato recalls.

“But then I started missing it, and once I got back into it that’s when things starting rolling. I think that’s because there was a new drive in it, there was more passion than there was before.”

Things just keep on rolling. Next year, “The Princess Protection Program” comes out, a movie Lovato filmed with best friend Selena Gomez, whom she met during auditions for “Barney.”

In the fall, she begins filming for her new Disney series, “Welcome to Mollywood.”

The pressure of living a life under constant scrutiny doesn’t discourage Lovato, who says she was born for show business:

“I knew from the second I stepped onstage. I was like, ‘Yep, this is what I want to do.’ “

The birthday bunch

Bandleader Doc Severinsen is 81. Drummer Ringo Starr is 68. Actress Shelley Duvall is 59. Actor Billy Campbell (“Once and Again”) is 49. Singer-songwriter Vonda Shepard (“Ally McBeal”) is 45. Actress Jorja Fox (“CSI.”) is 40. Actor Troy Garity (“Barbershop”) is 35.