Christina Hanson, 27, used a wheelchair and spent her life dedicated to helping others despite her own hardships, her family said.
Kelsi Mannhalter had posted on social media asking people to search for her cousin after the fire Monday ravaged Santa Rosa where Hanson lived.
Mannhalter later confirmed on Facebook that Hanson did not survive when the flames consumed her home.
"Just surreal," Manhalter posted. "I love you so much and am going to miss you sweet cousin. I can't say it enough."
Her father was found collapsed on the street in front of his home with third-degree burns and was taken to a hospital in San Francisco. Hanson had tried unsuccessfully to reach him as flames surrounded her apartment around 1:30 a.m. Monday, the San Francisco Chronicle reported.
Hanson was born with a spinal defect and lost her mother at 9 to lupus.
Still, her focus was always on others, her stepmother, Jennifer Watson, told the newspaper, describing her as "a very happy, social and positive person."
Hanson volunteered two days a week at an Alzheimer's residential care facility in Santa Rosa, where she would entertain residents.
She also taught herself sign language and interpreted for the hearing impaired.
"She loved helping people and loved her family," said Watson, who was with her stepdaughter the day before she died.
Her family wrote in an online obituary that Hanson "was granted her angel wings."