Grace VanderWaal: The 14-year-old pop star with an "old soul" sound

Grace VanderWaal became an instant star at 12 years old. She won a season of "America's Got Talent"  in 2016 by showcasing her original songs and raw singing ability. Music mogul Simon Cowell called her the next Taylor Swift and Rolling Stone says she's a pop prodigy.

She may be young, but when you listen closely, you can hear a bit of an old soul in her music. As CBS News' Vladimir Duthiers found out, the 14-year-old's got one foot in middle school and the other on center stage. Just don't call her famous.

"Famous is a very weird word," Grace told Duthiers at her home outside New York City. "I feel like – I feel like that's definitely not me."

Despite millions of fans, Grace still feels like she's on the "outskirts" of the fame bubble.

"And the middle of the bubble, that's, like, the really big celebrities…..I feel like I'm almost on the line of the bubble….And then the middle is just, like, so far away."

Fresh off her sold-out debut national tour, Grace is still grappling with her newfound success. For now, she's taking each step of her musical journey in stride. Last year she released her first album, appropriately named "Just the Beginning."

"I feel like each song is, like, really, really different than the other – 'cause I don't think I really know my exact style yet or my sound yet," she said. "I want my music to evolve to become more me. But I don't know. I think I'm just gonna, like, keep writing and just see where it goes."

She's already got a signature instrument. Inspired by a family friend, she taught herself to play the ukulele by watching videos online. Parents David and Tina VanderWaal have watched in awe as their daughter grew from the pig-tailed toddler who liked to sing to the artist she is today. 

"Everything was sort of led by her. I mean, even the story of how the ukulele came into play, she went and got the ukulele," David said. "And three months later, she's writing songs on her ukulele." 

Her mother almost couldn't believe it when Grace first sat down and played her a song she'd written. 

"But then you hear the song and you're, like, "wow, this-- this song actually has a bigger meaning to it," her mom said. 

"It's an old voice, old soul voice. But also, somehow it's an old soul lyrics too?" her dad added. "She's got music chops that came from someplace else."

This summer, Grace transitions to a much larger stage opening for Imagine Dragons on their Evolve tour.

"I think you need to figure out your balance," she said of being onstage. "'Cause if you think too much about that there's people around and – and how you're singing and looking and performing, I think that it won't be a good performance. Then on the other hand, you can't just be in your own world." 

How she stays on top of it all? Well, at times, she doesn't.

"I'm always falling behind and doing whatever. And – and then also just to keep my sanity, I just just don't think about that stuff. Like, don't think, 'I'm going on tour with Imagine Dragons and going to school and singing and writing' and, like, if you think that stuff, then you're put – then you've set that expectation that it's too much in your brain. Like, you've made yourself think that, you know?"