She was 13 years old when undergoing surgery for the treatment of obstructive sleep apnea, which caused her to stop breathing during sleep and cause other medical problems.
Nearly five years later, "Jahi died as a result of liver failure complications," said attorney Christopher Dolan.
She was operated on December 9, 2013, at the Children's Hospital and Research Center in Oakland. After the procedure to remove her tonsils, polyps and extra sinus tissue, Jahi was vigilant and talking to doctors and even asked for a popsicle.
According to her family, Jahi was in intensive care when she started to bleed and her heart was arrested. On December 12, 2013, she was declared brain dead. Her family disagreed with the explanation.
In the years since then, Dolan has released several statements that Jahi was well and even improved.
"A preliminary summary of death (death certificate) was completed by the hospital doctor treating Jahi and listing her cause of death as bleeding after liver failure," said the Darden in the statement announcing McMath's death. He goes on to say the death certificate, "notes that Jahi has been suffering from an anoxic brain injury for 4 years An anoxic brain injury occurs when oxygen is depleted from the brain Jahi suffered an anoxic brain injury as a result of heavy blood loss after surgery at the Oakland Children's Hospital in December 2013, when the medical staff did not treat Jahi or call a doctor after she had tonsilli, polyps and a soft palate to treat an apnea. "
CNN has not independently confirmed Dolans reports about what happened to the California teenager or his health.
Oakland Children's Hospital and Research Center claimed that they could not discuss Jahi's case in detail due to privacy laws.
She died at home, surrounded by her mother, Nailah Winkfield, stepfather Marvin Winkfield and sister, according to the statement.
Winkfield said she was "devastated by the loss of her daughter, who had demonstrated tremendous strength and courage." She added that she had "forced the world to reconsider the issue of brain death", relying on the extensive national debate about what constitutes a legal and ethical death over her daughter's case.
Some medical ethicists have said that the case is misinformed, that "brain death" is not death; that the body can live on somehow, and that is life.
Winkfield said she was grateful for the last four years she had with her daughter and although her daughter could not talk to her, "my daughter knew I was there and that I loved her, I knew that She said she loved me too. "
She said she left her job, sold her house and most of her things, and exchanged her savings for her daughter in New Jersey in 2014." It's tragic that I am now, after her death, my daughter can be. "
Dolan said that he will continue his pro-bono fight for Jahi, "through the civil suit filed in the Northern District The California District is scheduled to have its prepared death certificate undone, and its death date was June 22, 2018
In the meantime, plans are being made for Jahi, who was 17 when she died California.
CNN's Ed Payne. Catherine E. Shoichet, Jason Hanna, Ashley Fantz, Joe Sutton and Nadia Kounang have contributed to this report