Ariel Johnson is on a ventilator after suffering from smoke inhalation, according to her grandmother, Carolyn Payne.
Ariel's babysitter, Jackie Allen, 42, was killed in the fire on Thursday..
In a separate lightning strike during the same storm, 28-year-old Angelo Santucci was struck by lightning while working on a billboard in Gary.
Payne says the child was supposed to be in the care of her foster mother.
"The provider left Ariel with her son, her adult son, and unbeknowing to her when she got home, lightning had struck, which is a natural disaster - but still - why was she left with this guy?" Payne asked.
Payne says she cannot obtain custody of her granddaughter and Ariel's 3-year-old brother because she is not a resident of Indiana.