Gwynn taught physics at Rhyl Grammar School and later worked as an assistant account at the Government Exchequer and Audit Department.
Gwynn also authored multiple books and short stories, won awards during her career, promoted the Welsh language by being a member of four committees and served as president of two societies.
[1] Her father encouraged her to become interested in current affairs, read widely and become proud of her family roots in North West Wales.
[3] When Gwynn was ten years old, the family moved to Llangefni,[2] because one of her father's siblings had found employment as Cardiff's Regional Dental Officer for Wales.
[1] Gwynn defied the school's predominant English-language education, and assaulted an English mistress, who called the girls in the class "Welsh scum".
[1][3] Afterwards, she remained in Bangor to research X-ray crystallography,[4] and received a Doctor of Philosophy in physics in 1942,[1] becoming the first woman to graduate with such honours at the college.
[1] According to Meic Stephens of The Independent, she was unsuccessful in other occupations because the interview panel had not expected to meet a woman and did not want to accept that one had a degree.
[5][7] Gwynn reached a large audience by remaining independent from organisations or those from a narrow academic expertise and became a national celebrity in Wales.
[1] From these competitions, Gwynn authored Dau Lygad Du ('Two Black Eyes') in 1979, Caethiwed ('Captivity') two years later, Cwsg ni Ddaw ('Sleep will Not Come') in 1982, Torri'n Rhydd ('Breaking Free') in 1990 and Dim ond Un ('Only One') in 1997.
[3] That same year, Gwynn appeared in court because she did not pay her television licence fee in protest over the lack of Welsh-language programming,[2] and was issued a fine;[5] the BBC did not pick up her perception.
[5][7] Gwynn became a Druid (Welsh: Derwydd) in the Gorsedd of the Bards in 1985, earned a Bangor University Fellowship in 2002,[1] and was named the recipient of the Science and Technology Medal at the National Eisteddfod in June 2006.