[5] Once in Cairo, she worked at The New Zealand General Hospital, taking care of soldiers wounded and ill from the Gallipoli Campaign.

[8][9][10] Conditions where noted to have been extremely difficult, a quote from Willis describes:[8]A large ward of 80 beds took more than its number of stretcher cases, and here Doctors, Nurses, Orderlies and Padres worked hard in the sorting of them, removing mud and filthy garments from those poor fellow who had come straight from the mud filled trenches.

We washed and fed them, while next door, in the huge operating theatre containing three tables, Surgeons, Assistants, Sisters and orderlies carried on for periods of up to 24 to 26 hours pausing only for meals and coffee.

Sometimes because of the pressure of work, the theatre staff had no change of garments during 6 to 8 operations, stopping only to plunge their gloved hands under running water and disinfectant.

[13] In 1919, Willis was appointed assistant to the matron in chief of the New Zealand Army Nursing Services, Hester Maclean.