Once in the hospital, doctors diagnosed her with pneumonia.
The sad confirmation comes one year after Nickerson - who was best known for playing gum-chewing Violet Beauregarde in the 1971 film - suffered a severe stroke.
She was placed on life support, but on Wednesday her family told TMZ they had taken Nickerson off her respirator.
She had a pacemaker inserted shortly after, but was still at high risk for additional strokes and, according to Jasmine, would "likely require 24 hour care for the rest of her life".
Denise Nickerson taken off life support a year after suffering stroke. Furthermore, they stated that her lungs and brain activity are too weak.
"We are sitting here with her just trying to keep her comfortable and let her know it's okay". It's the worst. She's breathing on her own but they can't remove the ventilator today because they don't think she has the strength to cough and not aspirate.More news: Information Commissioner's Office plans £99m Marriott fine
More news: Spanish court rules Julio Iglesias is father of 43-year old man
More news: Manchester United Enquire For Southampton Midfielder
He said his wife Jasmine gave up her full-time job to care for Denise and they haven't been making enough income, causing them to struggle financially.
Jasmine spoke about her health situation via Facebook last June.
"He's never really experienced a major loss like this", she posted. "He says to me a few minutes ago that she won't ever get to see or hold or know her granddaughter".
In 2016, she paid her respects to Willy Wonka actor Gene Wilder when he passed, noting that he was "so talented and kindhearted".
In Willy Wonka & the Chocolate Factory, Nickerson played one of five children to win a Golden Ticket to take a tour of Wonka's mysterious factory.
In 2018 the Denver, Colorado resident had a pacemaker put in, but she had a hard reaction to it and became 'agitated'.
She had previously also starred in educational children's show The Electric Company, soap operas Dark Shadows and Search for Tomorrow, and an episode of The Brady Bunch, before quitting acting in 1978 to become a nurse.