Ruth Horowitz, born around 1943, is the sister of David Horowitz. She was raised alongside him in a communist 'red diaper baby' household in Sunnyside Gardens, Queens, New York, led by their parents, Phil (Philip Norman Horowitz, born 1904 in Mozyr, Russian Empire, died circa 1986 in Queens) and Blanche (Brown) Horowitz. Both parents were public high school teachers—Phil taught English at Seward Park High School for 28 years, Blanche taught typing and stenography at Girls' High School in Brooklyn—and longtime members of the Communist Party USA who quit after Nikita Khrushchev's 1956 report on Stalin's crimes. The family enjoyed cultural enrichments including piano, dance, and art lessons; attendance at concerts, ballet, and theater; a home filled with books; summer vacations; and camp. In 1953, when Ruth was 10, her father was fired by the New York City Board of Education during McCarthy-era purges, leading to family hardship, her mother's disability retirement, and emotional distress for Ruth. She earned a BA in Romance Languages from City College of New York (initially left after her second year in 1960, later returned to complete) and a Master's degree in Social Work from Columbia University School of Social Work. Her career included working as a nursing aide at Payne Whitney Psychiatric Clinic (1961), social investigator for the New York Welfare Department (10 years, active in 1965 Social Service Employees Union strike), in consumer education (CHANCE program), and as a high school librarian (1986–2006, retired after 20 years). In 1960, she traveled to Paris for a year. She lived in Park Slope, Brooklyn, before moving to Cape Breton, Nova Scotia, Canada, in the early 1970s due to urban decline and a desire for rural life. She married Ian, a Vietnam War resister and former abstract sculptor in wood and marble (now retired, focuses on land preservation, trails, gardening, and homesteading chores), a year after arriving. They have homesteaded in the woods of a small Cape Breton town since 1974, growing their own vegetables. Their son, Robin Horowitz (born 1980), lives in Maine with his family, including two grandsons. Ruth dabbles in painting, writing, and gardening, contributing articles to the Sunnyside Stories website about her childhood to counter political narratives.