On 4 January 1942, under Navy orders to take her children to safety and return with specialist equipment being made in Australia, Dr. Alexander and her children were evacuated to New Zealand by a Short S23 C flying boat.[8][9] After the Fall of Singapore on 15 February, she was stranded in New Zealand. She had no information about her husband for six months, and then was misinformed that he was dead.[10] Whilst in New Zealand, Alexander became Senior Physicist and Head of the Operational Research Section of the Radio Development Laboratory in Wellington in 1942, where she remained until 1945.