Vega grew up in Union City, New Jersey. At the age of fifteen, inspired by Jack Kerouac's On the Road, she travelled to Manhattan to become involved in the Beat scene there.
In 1962, Vega moved to Europe with her painter partner Fernando. After his sudden death, she returned to New York and then moved to California. Her first book, Poems to Fernando, was published by City Lights in 1968.
Since then, she has published more than a dozen books, including TRACKING THE SERPENT: Journeys to Four Continents (1997) which is a collection of travel writings.
In the 1970s, Vega has worked as an educator in schools through various arts in education programmes and in prisons through the Incisions/Arts organisation. She has served on the PEN Prison Writing Committee.