Oct. 1 (UPI) -- Sia had a special gift for dancer and frequent collaborator Maddie Ziegler on her 16th birthday.
The 42-year-old Australian singer took to Instagram Sunday after surprising Ziegler with a brand new Audi.
Sia shared a slideshow of photos and videos of herself with Ziegler and the car. The pictures show Sia embracing Ziegler as they celebrate.
"Happy Birthday to my most special noonoo @maddieziegler," Sia captioned the post.
"sweet sixteen <3 can't believe this car is actually mine!!" Ziegler wrote.
Ziegler has appeared in several of Sia's music videos, including "Chandelier" and "Elastic Heart," and joined the singer on tour in 2016 and 2017. She described Sia as a "second mom" in an interview with People in November.
"We have the best time together," the dancer said. "She teaches me how to cook and new things about life."
"It doesn't feel like work when we're together anymore," she added. "It's really just a bond that we have. She's my second mom."
Ziegler came to fame on the Lifetime series Dance Moms.