Millis was born in
Melbourne in 1922, the fifth child of six. She attended high school at Merton Hall,
Melbourne Girls Grammar, but had to leave before completing her studies when her father had a heart attack. She attended business college, then worked for a customs agent and then as a technician at the
CSIRO. Millis matriculated part-time, taking two years to complete her high school studies. The
University of Melbourne refused her entry into the
Bachelor of Science; however, she could gain entry to the degree of agricultural science. In 1945 she graduated with a BAgSc, and went on to complete a master's degree in 1946 studying the soil organism
Pseudomonas. Millis travelled to
Papua New Guinea with the Department of External Affairs to teach women agricultural methods. However, her posting was cut short due to serious illness that almost claimed her life and she was airlifted to hospital in
Brisbane. After recovering from her illness she applied for a Boots Research Scholarship at the
University of Bristol. She spent three years at Bristol working on the fermentation of
cider, and microorganisms that can affect the process. This led Nancy in her lifelong passion in anything that ferments. She died on 29 September 2012, aged 90. ==Honours and legacy==