"We, her family, are devastated by her passing and unimaginable loss," the Marczewski family said, according to a statement provided by NBC.
Known by the stage name Nightbirde, she appeared in season 16 of America’s Got Talent and performed an original song called It’s OK.
During her performance, Marczewski shared the story of her cancer diagnosis and revealed it had spread to her lungs, spine and liver. However, she remained positive and upbeat throughout her audition.
"You can't wait until life isn't hard any more before you decide to be happy," she told the judges.
She was given a standing ovation by the judges and audience as well as the coveted golden buzzer by Simon Cowell, which meant she was automatically advanced to the next round of competition.
However, she had to drop out saying that her health had taken a “turn for the worse”. During an interview on the show, Marczewski said it was "beautiful to see the world welcome that song into their own dark night".
"I'm overwhelmed by it," she said.
Her audition has been viewed more than 39.6 million times since appearing on YouTube in June 2021.
After news of her death, America's Got Talent paid tribute to the singer. "Your voice, your story, and your message touched millions. Nightbirde will always be a member of the 'AGT' family. Rest In Peace, Jane."
Host Terry Crews also shared his condolences. "We are saddened to learn about @_nightbirde's Passing. Our Condolences goes to her Closest Family & Friends in such of This difficult time. We Love you, Nightbirde," he wrote on Instagram.
Meanwhile, AGT judge Howie Mandel tweeted that she was a "bright inspirational light in our all lives" and said that although he was sad to hear about her death, he felt lucky to have "met, heard and known her".