[1][4] Rigg went on to complete a Master of Science degree with first-class honours in botany at Canterbury University College, graduating in 1952.

[7] She was awarded a Fulbright grant to travel to the United States, and studied at Vassar College from 1952 to 1954, earning a Master of Science degree.

[8] After returning to New Zealand from the United States, Helen Hughes taught at secondary schools in Christchurch and later Wellington.

[4] In 2017, she recalled that jobs for women in science at the time were hard to come by and there was "a bit of an old boys network operating".

She then worked for DSIR (Department of Scientific and Industrial Research) developing Environmental Impact reports.