On completing her Anthropology degree at Edinburgh University in 1998, Antonia worked as a television researcher and producer. During this time she worked on Big Brother and documentary shows for ITV, Channel 4, Channel 5 and Sky One.
Antonia left television in 2003 and took her talents to Lionhead Studios where she worked as associate producer on adventure game, Fable. She then went on to produce Fable: The Lost Chapters on X-box and PC before leaving to set up Infernal Development. In 2005 Antonia joined Kuju London as senior producer and development manager to oversee the early stages of Battalion Wars 2 and another unannounced project on Wii. She left to have a baby in mid 2006 and returned to work in March 2007, joining Team Works Productions.