Cille Gad was born and grew up in Bergen and received instruction in Greek, Latin, and Hebrew by her father, who was a clergyman. She became pregnant out of wedlock by a Dutch sailor, Matthias Boudaan, had a clandestine birth and was subsequently accused of child murder and sent to prison. When her death sentence was commuted to a fine in 1707, she went to Copenhagen, where she later died.
Cille Gad wrote honorary verse in Latin, printed in Thomas Jacobæus' Dissertatio de oculis insectorum, Copenhagen, 1708. She also wrote unpublished poems in Latin to Otto Sperling the younger, describing her incarceration. These are kept at the Danish Royal Library.