She was being shifted from Hegdewar hospital.
Police have so far arrested six persons in connection with the case.
The girl had allegedly attempted suicide on April 20 by consuming sleeping pills.
The crime came to light when the parents of the victim, residing in Farsh Bazar in east Delhi, approached police and complained about the incident.
According to the complaint, the victim was kidnapped from near her house by the eight people, including one person whom she addresses as "uncle", on March 16 and forcibly taken to Loni in Ghaziabad.