Gemma studied on the MFA Theatre Directing at Birkbeck (University of London), and on the National Theatre Studio Directors Course. Her directing work includes Hitting Town by Stephen Poliakoff (Southwark Playhouse); Airswimming by Charlotte Jones (Courtyard Theatre); Mad Forest and The Laramie Project (Cockpit Theatre); and Scarberia by Evan Placey (York Theatre Royal).

In 2010 she formed High Hearted Theatre with writer Marcelo dos Santos, creating original work for non-conventional theatre spaces placing an emphasis on narrative and new writing. Productions for the company include Lovers Walk (Brighton Fringe Festival and Southwark Playhouse); Births Marriages and Deaths (Manor Farm, Ruislip), Cheer up, this is only the Beginning (Liverpool Everyman and Playhouse) and This Place Means (Greenwich + Docklands International Festival 2012).

Gemma is also a founder member of Forward Theatre Project, an Associate company of Paines Plough.