According to the NYC Death Index at the NY Public Library, a Janet Adrian died in Manhattan on 23 December 1960, age 41 years. The Manhattan Death Certificate number is 27499.
If you think this is the correct person, you should be able to obtain a copy of the death certificate from the NYC Department of Health, Office of Vital Records. You can get more info at: http://www.nyc.gov/html/doh/html/vr/vr.shtml
and can order online through VitalChek.