The victim died early this morning, Namdev Chavan Zonal Deputy Commissioner of police told PTI.
The girl, who was admitted in a critical condition to the Gurunanak hospital in Bandra, was on ventilator since December 22 after she was attacked by her college mate Nikhil Bankar several times with a knife, injuring her seriously in different parts of the body.
The 22-year-old boy also committed suicide after the incident that day.
Nikhil and the victim were studying management at the college and recently had a break-up.
According to police, Nikhil had accosted the girl and three of her friends while they were on their way to the classroom in the morning, and during a heated argument between the two, Nikhil whipped out a knife from his bag and slashed her several times.
Later, Nikhil stabbed himself around 4-5 times and also slashed his neck. He had died during admission to the hospital that day itself, police added.