De Angelis began her career in the 1980s as an actress with the Monstrous Regiment theatre company.
In 1987, her play Breathless was a prize winner at the 1987 Second Wave Young Women's Writing Festival.
Wanderlust examines Victorian colonialism and Ironmistress is a verse play exploring Lady Charlotte Guest's factory ownership.
As a librettist, De Angelis contributed to the opera The Silent Twins (2007), composed by Errollyn Wallen, which is based on the case of June and Jennifer Gibbons.
[3] De Angelis tends to write to commission and several of her plays have been produced by Max Stafford-Clark's Out of Joint theatre company.