Kavita, 57, was admitted to the P D Hinduja hospital on Saturday. She had slipped into coma and was on ventilator, hospital sources said.
Her last rites would be performed at Shivaji Park crematorioum tomorrow, police sources said.
Her children -- two daughters and a son -- have consented to donating her organs to needy persons, a statement from the hospital said.
Kavita, a college professor, was earlier declared brain dead by the hospital.
Kavita had also been demanding better weapons, training and facilities for police personnel.
Karkare was killed along with Additional Police Commissioner Ashok Kamte and senior police inspector Vijay Salaskar when terrorists fired at their vechicle near Cama Hospital in south Mumbai on the fateful night.
