Sundas Balwa, 33, and Shakir Alshahien, 37, were charged with endangering the life of a child. Balwa was also charged with criminal negligence of a disabled person.
Parwin Husan died Monday. An autopsy was conducted but results were being withheld pending further investigation by police, a medical examiner's spokesman said.
Police said Husan appeared to have been tied to a radiator in a third-floor bedroom and somehow broke free, then jumped or fell from the window. Police said Husan had apparently been left alone in the apartment.
Neighbors said the girl often was left home alone and had fallen last month while unsupervised.
Balwa and Alshahien were being held at the Cook County Jail. Their court appearance was set for May 20.
The Department of Children and Family Services has taken Husan's 3-year-old brother and 5-year-old sister into custody and placed them in a foster home. The agency had no prior contact with the family, spokeswoman Martha Allen said.