Meet the New 'It' Girl Maddie Ziegler

— -- Maddie Ziegler’s turn as the pint-sized dancing sensation in the music video for Sia’s multi-platinum hit “Chandelier” began with a single tweet.

“Sia just tweeted me and said, ‘I’m a fan. I really wanna work with you! Will you be in my video?,’” Maddie, known from the reality TV show “Dance Moms,” told ABC News' Mara Schiavocampo.

“My whole team, my mom and everyone, they were like, ‘Uh, so she wants to work with you? Is this fake?’” she recalled. “None of us thought it was real because this stuff doesn’t usually happen. But obviously, we got a hold of her and we did contact her, and two weeks later I flew out to L.A. and I learned the video, like, the choreography.”

The music video, with its magnetic choreography, rocketed to viral success with more than 560 million views, launching 12-year-old Maddie into stardom.

“I thought it would be just a little, you know, tiny little video, nothing would happen to it,” Maddie said. “I never thought it would blow up, and now it’s a lot of celebrities and a lot of stars are knowing my name, and it’s so cool.”

For years, Maddie has been a budding star on “Dance Moms.” It was “Chandelier” that swung new life into the tween’s career, with big performances on shows including “Dancing With the Stars” and “Jimmy Kimmel Live.”

“My life has changed in so many different ways,” Maddie said. “I never would’ve performed at 'SNL' or ‘Ellen’ or anything like that if it weren’t for ‘Chandelier’ and Sia."

"She’s helped me so much, and I really love her a lot,” Maddie said of the music star.

The feelings appear to be mutual as Sia cast Maddie again as the lead in the music video for her latest hit, “Elastic Heart," alongside actor Shia LeBouf, and had her perform with her at this year’s Grammys.

"It was amazing,” Maddie said of the awards show. "I never thought I’d be dancing at the Grammys, yet alone actually just being there. And the first time I went to the Grammys I never thought I’d be performing, and I did. And getting to do it with Kristen Wiig and Sia is just the coolest experience.”

“Sam Smith came up to me and he told me that he was a fan,” Maddie said of the night’s big winner. “And I was freaking out because I’m his biggest fan, and I was freaking out because I was walking behind Beyonce for like a straight 10 minutes.”

Now, Maddie is stepping into new shows, taking her talents to the runway as a fashion correspondent for Elle.com.

“I am just watching the shows and giving my feedback to them, and it’s been amazing,” Maddie said at last week’s New York Fashion Week. “I’ve been to so many amazing shows, and I’m really loving fashion right now -- so it’s so cool.”

Despite the opportunities, Maddie said dance is still her first love.

“I’ve been doing a lot of acting practice and a lot of singing practice, but dance is definitely my No. 1 because I’ve been doing it since I was 2 years old and I want to be a professional dancer when I grow up,” Maddie said.