Neville decided to stop parts of her leukemia treatment to allow for Sierra's white blood cells to build back up. Neville said it was a risk, but Sierra's immune system was the last weapon they had.
"She was so sick at that point that we had no choice but to let her white blood cells fight that infection," said Neville.
Neville said she expected the rush of white blood cells would cause certain parts of Sierra's body to become inflamed. And she anticipated Sierra's condition to get worse.
In fact, she thought it would be safe to tell the Kings that Sierra may not survive. She said she told the Kings to "say their goodbyes."
"I remember we told her that we loved her and if she needed to go she should go, but she's always welcome to stay," said Walter King.
But Sierra did make it through the night.
As each day went by, the infection subsided, while the leukemia continued to be kept at bay.
"You just take your best expertise and make what you think is the best possible decision," said Neville. "Did I know it was the best at the time? At the time, I don't think anyone could've known. ... It was the best possible decision in the worst situation."
Sierra was only one of four in the nation to overcome this type of infection, Walter King said doctors told them.
"You just don't survive it, they said. But she did, that little stinker," said Walter King.
Sierra has remained in remission for a year. The leg braces she now wears as a result of the nerve damage caused by the chemotherapy treatments are the only remnants of her disease and near-fatal infection, she said.
"I always felt very loved, so I never felt alone fighting through it," said Sierra. "I never wanted to give up, and I think that's because of all the love and support that I had."
Indeed, Neville said there were many times during Sierra's illness where conventional means of treating Sierra would not have worked. She said the choice Sierra's family made to stick by Neville's treatment decisions contributed to Sierra's survival.
"I've seen so many cases, and the fact that she has battled back from it all is remarkable," said Neville. "I think there's an unquantifiable piece of the human spirit that makes this possible."