Her 13-year-old, Jahi McMath, was sitting up in bed, her hospital gown bloody, and holding a pink cup full of blood.
"Is this normal?" Winkfield repeatedly asked nurses.
With her family and hospital staff trying to help and comfort her, Jahi kept bleeding profusely for the next few hours then went into cardiac arrest, her mother said. The girl was declared brain dead on Dec. 12.
Now, the hospital wants to disconnect her life support, the family says, but their lawyer Christopher Dolan has refused permission and is trying to keep Jahi on a ventilator through the holidays while the family obtains another opinion on her condition and reviews medical records. A court hearing was set for Friday.
Hospital officials said they couldn't discuss the case because the family hasn't given them permission to do so.
In a statement late Thursday, Dr. David Durand, the hospital's pediatrics chief, wrote of Jahi's case: "We are unable - without the family's permission - to talk about the medical procedure, background or any of the details that are a part of this tragedy.
"We implore the family to allow the hospital to openly discuss what has occurred and to give us the necessary legal permission - which it has been withholding - that would bring clarity, and we believe, some measure of closure and deeper understanding of this medical case," the doctor added.
In an interview at Children's Hospital Oakland on Thursday night, Winkfield described the nightmarish turn of events after her daughter underwent tonsil removal surgery to help with her sleep apnea.
She said that even before the surgery, her daughter had expressed fears that she wouldn't wake up after the operation. To everyone's relief, she appeared alert, was talking and even ate a Popsicle afterward.
But about a half-hour later, shortly after the girl was taken to the intensive care unit, she began bleeding from her mouth and nose despite efforts by hospital staff and her family.
While the bleeding continued, Jahi wrote her mother notes. In one, the girl asked to have her nose wiped because she felt it running. Her mother said she didn't want to scare her daughter by saying it was blood.
Family members said there were containers of Jahi's blood in the room, and hospital staff members were providing transfusions to counteract the blood loss.
"I don't know what a tonsillectomy is supposed to look like after you have it, but that blood was un-normal for anything," Winkfield said.
The family said hospital officials told them in a meeting Thursday that they want to take the girl off life support quickly.
"I just looked at the doctor to his face and I told him you better not touch her," Winkfield recalled.
Hospitals do a barrage of sophisticated tests to determine brain death, said Dr. Cristobal Barrios, an associate professor and a trauma and critical care surgeon at the University of California, Irvine. He is not involved in Jahi's care and spoke about general hospital protocols.
The tests include touching a patient's cornea to elicit a blink, moving a breathing tube to stimulate a gag reflex, tickling the back of the throat to bring on a cough, and applying pressure or pain.
If the patient fails to respond to all of those tests, doctors remove the breathing tube for a few minutes. If there is any brain activity, the patient should begin breathing within a few minutes, he said.
In some cases, doctors will also draw a blood sample, add radioactive tags and re-inject it into the body to track where it flows. If the blood doesn't flow to the brain, Barrios said, there is no brain activity.
Generally, two teams of specialists must run the tests and determine independently that the patient is brain dead, he said. At UC Irvine, those evaluations must take place 12 hours apart if the patient is a child.
Barrios said it's not unusual for family members to resist a diagnosis of brain death.
While the hospital is not obligated to keep life support going after that diagnosis, Barrios has left brain dead patients hooked up for up to five days while family members move toward acceptance, he said.
"I understand why sometimes for families it's devastating and confusing," he said.
Associated Press Writer Gillian Flaccus in Santa Ana contributed to this report.