Susannah started her career in documentaries at the BBC, working for independent production companies such as Brook Lapping, Wall to Wall, Mentorn and Oxford Film and Television. She has worked all over the world from Senegal to Afghanistan, India and Zambia, and has produced many award-winning documentaries such as Michael Moore's Sicko, the docu-drama Oil Storm for FX Channel, War Oratorio a feature-length music film set in 3 war zones, and Chopin Saved My Life which was nominated for the audience awards at the UK National Documentary Festival. She has also directed several films, including the BBC docu-drama Boarding School Bomber starring Adam Deacon; and helped devise the highly-acclaimed and BAFTA-nominated drama series Southcliffe for Channel 4 written by Tony Grisoni and starring Rory Kinnear.

Susannah has produced several landmark series including Simon Schama's The American Future for BBC/PBS; Niall Ferguson's Civilization: Is the West History (Channel 4/PBS) and China: Triumph and Turmoil (Channel 4/PBS); as well as groundbreaking documentary formats such as the BAFTA-nominated 8-part BBC series Keeping Britain Alive, which placed over 100 cameras across Britain's National Health Service on a single day. Susannah and Simon first worked together on the multi-BAFTA-winning Channel 4 drama starring Mark Rylance about UN weapons inspector David Kelly, The Government Inspector and have finally joined forces again, ten years later.

Susannah joined LIGHTBOX in October 2013 to build up its slate across a range of genres and platforms, and to nurture talent for LIGHTBOX both in the UK and USA.