The little girl died the next day at the hospital.
Melinda Sayers' 11-month-old daughter, Abigail, was born premature and spent the majority of her young life as a patient at Seattle Children's Hospital. The family gained attention late last year when Seahawks star quarterback Russell Wilson visited Abigail at the hospital.
After undergoing five brain surgeries, Abigail was finally deemed healthy enough to return home earlier this month. But prosecutors say the day before Abigail was set to be released, Melinda Sayers lit a candle in her living room and opened the valve on her daughter's medical oxygen tank to start and fuel a fire.
She then called 911 to report the fire and left the home with her 2-year-old son, prosecutors said.
In an interview with detectives, Sayers claimed she opened her bedroom door, saw black smoke, then lowered her son from her bedroom window and climbed out, adding she didn't know how the fire started, prosecutors said.
But investigators say they found a hand-held butane lighter on the living room couch and felt the story didn't match the evidence.
This week, Sayers was interviewed by detectives again where she admitted to starting the fire, stating she didn't want her daughter to come home, prosecutors said. She was arrested Thursday and booked into the Pierce County Jail.
"She stated that she lit a candle and used the oxygen and moved some furniture around to start the fire," said Ed Troyer with the Pierce County Sheriff's Office.
In court Friday, Sayers pleaded not guilty to charges of first degree arson and filing false insurance claims. She's being held on $200,000 bail.
Detectives say they are still investigating the amount of Sayers' financial gain from the arson. Troyer said detectives will also continue investigating the case.
"It wouldn't be prudent for us not to look at the death of Abigail," he said.