Jahi McMath, 13, underwent a surgery to remove her tonsils, adenoids and uvula at Children's Hospital & Research Center Oakland on Dec. 9, the Los Angeles Times reported. Three days later, she was declared brain dead.
Despite a consensus among medical experts that the girl's body would deteriorate, her family had her moved to an undisclosed extended care facility.
The Alameda County coroner later issued a death certificate for Jahi without performing an autopsy.
On Wednesday, Nailah Winkfield, Jahi's mother, took to Facebook to deny claims that her daughter had died.
"Despite what people say about my daughter being dead and how I must be ignorant not to get that, I can tell you that she is much better physically since she has left Children's Hospital and I see changes that give me hope," Winkfield said in a post on Facebook.
The mother went on to thank people "who view my daughter as the sweet, innocent, 13-year-old girl that she is and not a dead body or a corpse, I deeply appreciate that."
"God can overcome all things and I believe that his will has yet to be fully revealed," Winkfield wrote. "I love Jahi and where there is love, there is hope."
Arthur Caplan, director of the division of medical ethics at New York University Langone Medical Center, said Jahi's case may compel other families to "ultimately say, 'I'd like to take this body home and wait for a miracle.' That would be a public policy of disrespect for dead bodies."
"The ability to get clear about brain death has been a real obstacle," he said. "This hasn't helped at all."