[2] At the age of 16, FitzGibbon joined her sister Mary as a nurse aide at Seacliff Mental Hospital, near Dunedin.
[4] FitzGibbon nursed at base hospitals in Egypt and in France, and on an ambulance train near the front line.
In this role she travelled extensively throughout New Zealand, visiting and advising Plunket nurses and assisting branches to develop.
[2] FitzGibbon collaborated with Dr Helen Deem, the Plunket Society's medical advisor, to develop and co-write a manual for New Zealand mothers.
Titled Modern Mothercraft: A Guide for Parents, it was first published in 1945, and reprinted nineteen times over subsequent years.