[2] Gwilym joined BBC Wales in the 1980s and produced and directed numerous documentary television programmes over two decades.
[3] In the late 1980s she produced documentaries about various women in politics, including Eugenia Charles, Simone Veil, Tatyana Zaslavskaya and Benazir Bhutto.
[1][5] Gwilym was hired by S4C, a Welsh-language television channel, in 2004 as the editor for factual programmes and co-productions.
[2] Her productions for S4C included O'r Galon (From the Heart), Wynebau Newydd (New Faces), Cefn Gwlad (Countryside), Ffermio (Farming), and nature programmes hosted by Iolo Williams.
[3] She was a content editor on the current-affairs programmes Y Byd ar Bedwar (The World on Four) and Wedi 7 (After 7).