The 15-year-old is set to have a hearing in Gloucester County family court on Tuesday.
In the weeks ahead she'll be getting psychological testing and a lawyer has been retained for the juvenile's legal battle ahead.
"These are the same identical charges if you were an adult or a juvenile, but you're heard in a different court system," said Gloucester County Prosecutor Janice Melfi.
Authorities say the Saturday morning fire was set when the girl poured gasoline in the second floor of the home and ignited it. The damage was contained to the second floor.
"It's terrible for a youth. They don't fully realize the full implications," said neighbor Bill Donnachi.
The teen and six other family members were injured, including two who were taken to a burn center in Pennsylvania with internal burns.
The girls' mother, identified as 39-year-old Sara Otero, was among the hospitalized but was released on Monday afternoon. The girl's uncle was also injured.
Otero and 42-year-old Jimmel Still share ownership of the home. Still, along with two stepchildren - including the accused - plus their young cousin were treated for minor fire-related injuries.
The suspect is being held at the Camden County Juvenile Detention Center.
"They always seemed like great people as far as I could tell," said Donnachi. "It's a real shock."
One neighbor said the prosecutor should go all out to see that the accused teen is locked up for a long time.
"If it was me I would charge her to the full extent. Do it all the way," said neighbor Belinda Rogers.
Prosecutor Melfi said that, if convicted, the 15-year-old could serve state prison time.
