Jackelin Vilorio was admitted to the hospital Friday after the sport utility vehicle struck her about 7:15 p.m. at Madison and Roosevelt streets in Rocky Point, police said.
A man who answered the family's phone and identified himself as David Velasquez, the girl's uncle, said the parents were at the hospital and were making funeral arrangements.
"She was connected to a machine because she had a brain injury," said Velasquez, who said Jackelin died yesterday afternoon. Police confirmed she was pronounced dead at the hospital Sunday.
The parents later declined to be interviewed through a hospital spokesman.
Robert Dougherty, 20, was driving a 1990 Jeep south on Madison Street when his vehicle ran into the girl. He was not injured, and no charges were filed.
The Jeep was routinely impounded for a safety check and the investigation is continuing, officials said.
Detectives ask anyone with information on the accident to contact the Seventh Squad at 631-852-8752 or call Crime Stoppers anonymously at 800-220-TIPS. All calls will be kept confidential.