Her chemotherapy was individually tailored to her mother's cancer and she is responding, according Gasper, who is serving as the family spokesman.
"The tumors aren't multiplying and the new ones have shrunk," she said. "Her medication has to constantly be changed for her size as she grows. The cancer cells also constantly mutate, so the chemotherapy is constantly changing."
As for James Cox, "He's very tough," said Gasper. "He is a military man with 18 years in the Air force. He works in crisis mode and now he's focusing on Addison. Obviously it's a lot to deal with losing his wife and now knowing his daughter is going through something similar."
So far, she is able to live at home and is pain free. Her father says, "She's a fighter like her mom."
James Cox, who works in emergency management, said he and his David are in counseling, but keeping the family together emotionally has been hard.
David is perfectly healthy, but he has been traumatized by the sudden loss of his mother and has become protective of his father.
Cox tells his son, "Remember how sick Mommy was when she died. She's not in pain anymore."
"He's not going to understand for a couple of years," said Cox. "He latches on a couple of times a day and says he wants his mommy."
He stays tough, because his wife was.
"She had an aggressive, strong personality," he said. "Briana said how to deal with it -- we could wallow in self-pity or knock the dirt off and move on."
The family has been getting help from Cox's mother, who flew in from Texas. He just returned to work for the first time today.
Cox said that his wife always paid attention to her health. She went to all her routine check-ups after her 2006 surgery. All her margins were clear and no other spots were every found.
Doctors said that some of the symptoms associated with the metastasized cancer could have mimicked pregnancy -- mild memory loss and fatigue -- which delayed diagnosis.
"Briana did what she was supposed to do and somehow got stage 4 cancer and nobody knew it could affect the child," he said. "We need more research and more information."
In the meantime, Cox waits for a miracle and is grateful to those who are jumping in to help.
"We've had a lot of support from the community, the police department where Briana worked," he said. "Everybody."
The Phoenix Police Department fundraiser is on March 3 from 10 a.m. to 3 p.m. at its Air Support Unit, 102 E. Deer Valley Road.
Donations can be made to the "Cox Family" donation account at Arizona Federal Credit Union. Account #826604. For more information, call Sgt. Keith Politte at 602-999-2214.