Koval's parents were Jewish refugees from Poland, arriving in Australia in 1949. Koval was educated in Melbourne and has worked as a freelance writer and journalist. She has become well-known as producer and presenter of Books and Writing and has co-presented Australia Talks Books on ABC Radio National. From 2006 to 2011, Koval presented The Book Show, a daily weekday programme also on ABC Radio National. She gave the 13th Annual Manning Clark Lecture at the National Library of Australia, Canberra, Australian Capital Territory, 7 March 2012.