The Sonny with a Chance star is wowed by red-carpet shout outs and 20,000 Twitter fans!

Credit: Jill Johnson/JPI

A new name is poised to join the ranks of Disney megastars: Tiffany Thornton, better known as teen queen Tawni Hart on the Disney Channel’s Sonny with a Chance.

When it comes to adjusting to life in Hollywood, some well-connected friends are helping out, including costar Demi Lovato. “Demi is beautiful and talented,” Thornton tells PEOPLE. “She’s a busy, busy girl. She and I have grown really close, like sisters, over the process of being on the show together.”

Thornton, 23, also thinks the Jonas Brothers, set to debut on their own Disney Channel show soon, are “such sweethearts. They’ve been raised to be so respectful, and they love their fans.”

Jonas Brothers’ Premiere

How would she know? The lucky actress got to hang out with the hot trio when she hit the red carpet for the first time at the premiere of Jonas Brothers in 3-D. “It was an honor to share the carpet with them,” she says.

Hailing from College Station, Texas, Thornton realized at the Jonas premiere just how big she’d become. “I had never had a moment where I’m walking across the street and someone yelled my name and people started screaming. That’s never happened to me before!”

She better get used to it, because Sonny is a hit. Keeping things in perspective – and starting her own her own Twitter account, therealTiffany – she says, “There’s pressure any time you’re in the spotlight. There [are] days when it’s hard. I try not to read comments online. But there are more days when it’s amazing. The support we get from people is overwhelmingly a blessing.”