Fensom is the eldest of four children of Sydney Leonard Fensom and his wife Marjorie Kate (Dance). She came to Australia from England with her family in 1947 on the S S Ormonde. Fensom began writing poetry as a child, and her first poem was published in the children's pages of the Australian Woman's Mirror in 1955. She attended St Peter's Collegiate Girls' School, and had various poems published in the school magazine from 1956-1959. Fensom graduated from the University of Adelaide with a BA in 1967 and completed an MA in Creative Writing in 1999.
Fensom married Kelton John Dingle in 1966, and they had two daughters. She was widowed in 1995. Fensom has been a committed Green activist, and a committee member of People for Public Transport and Rail 2000. Her work has been displayed as one of the Poems for Passengers. Fensom has served on the Conservation Council and has written for and edited the Friends of the Earth Chain Reaction Co-op periodical, Chain Reaction. She is an active member of the Kensington and Norwood Writers' Group and of Friendly Street. Some of her children's stories were read on the TV programme Mulligrubs in 1989-1990.
