Those in court say the girls, who are charged as adults, looked at their parents briefly in court Tuesday, though they offered no apparent expression or remorse.
Police say they found that several small fires had been set on the second floor of the home. The fire spread through the home while the family slept.
The parents, Nestor and Diana Fernandez, made it out of the home safely, as did the girls and the family dog.
"It happened at 3:45 in the morning, so we're glad to see that everyone got out of the house alive," Ossining police Detective Lieutenant William Sullivan told the Journal News.
No motive has been offered for the alleged arson, though the investigation is continuing.
Sources say the parents each have a child from a previous relationship. Nestor is Miranda's biological father and Diana is Pauline's mother.
The girls are due back in court on May 4.
