Among those at the prayer vigil was Jahi's youngest sister, Zaylah.
"Her mom was very sick and Jahi took over all the mother responsibilities. So it's just rough right now," said Darolyn Fox, Jahi's aunt.
Several hundred people were at the Paradise Baptist Church in Oakland praying for a medical miracle.
"I want to thank everybody that came out because a lot of these people don't even know my daughter, but they're still here praying for her," said Nailah Winkfield, Jahi's mother.
The 13-year-old girl is on life support at Children's Hospital Oakland where doctors have declared her brain dead. So far, no one has explained why Jahi went into cardiac arrest after routine tonsil surgery last week.
On Wednesday, the family's attorney issued a letter to the hospital demanding Jahi's medical records. Children's Hospital says it does not release the entire medical record while the patient is in the hospital because doctors are continually updating it.
"It's somewhat of a standoff. The hospital has agreed to back down. They said there's no timetable, but I have to assume that a timetable is coming," said Chris Dolan, the family's attorney.
Jahi's family says they will keep her on life support until she wakes up. Meantime, they're preparing for what could become a long and drawn out legal battle.
ABC7 News spoke with Dr. Jeff Burack, an associate clinical professor of bioethics and medical humanities at U.C. Berkeley and co-medical director of the East Bay AIDS Center. He says, brain death is a diagnosis made by two different doctors and it is irreversible. Regardless, Jahi's mother continues to hold onto hope and lean on her faith.
"She's a big part of my heart and I won't give up, even my shirt says I won't give up. And I could just see her face saying, 'Mom. Don't give up on me,'" said Nailah Winkfield, Jahi's mother. "I would never give up on my daughter. She deserves to live."
"Recovery in those situations is unprecedented, it just doesn't happen. Whether or not that's going to convince somebody who's praying and hoping otherwise is a different matter," said Burack from Alta Bates Summit Medical Center.
Under California law, a person who is declared brain dead is legally and physiologically dead. Jahi suffered cardiac arrest and was declared brain dead on December 12 and legally dead on Monday, Dec. 16.
The family's attorney served Children's Hospital with a cease and desist order Tuesday. The family says the hospital was going to take Jahi off the ventilator Tuesday after her latest EEG test showed no brain activity.
After their victory Tuesday, Jai's uncle Omari Sealey told us, "We're happy they backed off. You know, we're not on doctor's times anymore we're on God's time. It's provided us more time to get together and pray."
Jahi's mother Nailah Winkfield added, "I believe that God has the final say so for my daughter and I just want everybody to pray for her, everywhere."
The hospital claims that under California law, it has the legal right to remove the girl from life support because of her condition. It also says due to privacy issues it cannot "correct misperceptions created about this sad situation."
The girl's grandmother, who is a nurse, tells us they have a lot of questions about what happened after her surgery.