Daughter of Thomas Douglas Marsh and his wife Joan Violet, Judy came to Australia when she was three years old, and grew up in the country just outside Melbourne. She left school at the age of 16 to work as a clerk in an insurance company. In 1971 she married and came to live in Adelaide. She worked here for several years in secretarial work before beginning a teaching course at the University of SA (Magill Campus) in 1976. She has been teaching since 1979, and has completed a Bachelor of Education and an MA in Literature from Deakin University.
Her first marriage ended in 1988, and with it a long period of "writing in the cupboard". She says of her early writings that her first efforts were "the obligatory dark outpourings" of a childhood dominated by a loving but overly possessive and moody father. She says, "I poured my soul into these poems and then discovered that nobody really wanted to know" [personal communication]. In 1990 she married again, and her new husband, John Dally, encouraged her to write and to publish. "This newfound liberation," she says, "allowed me to write a lot of things out of my system until now, when I seem to have returned to leisurely, occasional writing of more lighthearted poems about teachers and children" .