At least nine people were injured in the blaze, which broke out on the sixth floor of the 17-story building at 540 East 169th Street around 6:30 p.m.
The girl was listed in critical condition but is expected to survive after officials said she jumped from a sixth-floor balcony to escape the flames and unbearable heat.
She landed on dirt, not pavement, and although she broke both legs, the fire chief says her landing may have saved her life.
"The little girl she stayed there and she wasn't moving at all, I thought she was dead, but everybody rushed to help her out," eyewitness Levar Chisolm said.
Linda Kemp, the tenant association president, and two neighbors shielded the girl from burning debris that was raining down before EMS could rush her to the hospital.
"When that child was there, that was my call to do what we do as human beings, and that was protect that baby that was on the floor," Kemp said.
Investigators say the girl's 17-year-old aunt tried to save her but was blocked by the flames. She reportedly suffered minor injuries.
"I don't know how the sleep is going to be tonight, but it's going to be a prayerful one because I'm going to pray that she recovers, and that she be all right," Kemp said.
In addition to the young girl and the adult in that apartment, seven firefighters suffered minor injuries.
More than 100 firefighters responded to the scene and had the fire under control shortly before 7:30 p.m.
The cause of the fire is not yet known. Fire marshals will investigate the cause.
Friends have set up a GoFundMe page to help the young girl and her family.
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