In 1977, she won a prize for a short story at the National Eisteddfod of Wales, and on more than one occasion she came close to winning the Prose Medal. 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. In 1999, she wrote her autobiography Ni 'n Dau: hanes dau gariad ('Us Two: the story of two lovers'), which discusses her views on religion and life experiences during her early years. 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, and was issued a fine; the BBC did not pick up her perception. She was one of five individuals to sign a protest to prevent English-only speakers from having an escort at the National Eisteddfod in Newport in 2004.