Gillian has had a diverse career editing feature films, MOWs, drama series, and documentaries, in a variety of genres. She has worked with many prominent and celebrated producers and directors in the Film and TV industry including David Shore, Moira Walley-Beckett, Naren Shankar, Mark Fergus, Vincenzo Natali, and Helen Shaver.

Gillian's editing credits include the highly acclaimed series, Orphan Black, for which she received two CSA Awards. She is the first Picture Editor to have won that award for two consecutive years for the same series. Her work on Orphan Black has also garnered her a DGC Award and two CCE Awards nominations. She has also earned a DGC nomination for Degrassi: The Next Generation, and a Gemini nomination for the series Todd & the Book of Pure Evil.

Some of her other credits include the series Anne, The Expanse, Houdini & Doyle, The L.A. Complex, and the feature films Seven in Heaven, for Blumhouse Productions, A Christmas Horror Story, for Copperheart Entertainment, and Compulsion, for Dimension Films.