Gillian graduated from Trinity College Dublin with a BA Hons in English and Drama. In relation to her actor training, she has been involved in master classes at the Abbey Theatre, Dublin with Anne Bogart from the SITI Theatre Company (New York) and Mark Rylance from the Globe Theatre, London. She has done physical theatre with Barabbas and Kaos U.K. She has also been a member of the Attic Studio Dublin where she studied screen acting.