Only this time, she was in for a special surprise. As Sizemore reached the end of her routine to Colbie Caillat's "Try," the pop singer herself appeared to sing the final lines.
As the applause and tears died down, Caillait told the little girl, "That was so lovely. Thank you for dancing to my song. You really are an inspiration to so many people."
"Thanks for giving it to me," Sizemore replied.
In May 2014, the Utah native had to undergo a below-knee amputation after a UPS truck ran over her right leg.
Before her live performance, the little dancer told Hoda Kotb and Kathie Lee Gifford that Caillat's song has empowered her in the aftermath of the tragic accident. "It inspires me to be who I am," she said.
During her interview, she also said that performing has been an important part of her recovery. "I'm having a lot of fun doing what I'm doing and I'm showing the world that I can still dance."
ALSO ON HUFFPOST:
HuffPost Parents offers a daily dose of personal stories, helpful advice and comedic takes on what it’s like to raise kids today. Learn more