Waltham Miss J. Gertrude Harrington of Waltham died Monday, October 4, 2004 at Mount Auburn Hospital, Cambridge. She was 90. Born in Waltham, a daughter of the late William A. and Violet G.M. (Ohnemus) Harrington, she was a lifelong resident. She graduated from Waltham High School in 1931 and from Framingham State College in 1935. She earned a masters degree in elementary education from Harvard University and taught for more than forty years in the Waltham public school system, retiring as assistant principal at Northeast School. She leaves her sister, Doris H. Foster and her husband Harry of Waltham, one niece and two nephews. She was also a sister of the late William Harrington. Funeral services are private.