Gilbertson trained as a teacher and in 1929 did a secretarial course with journalism in London. She saw an amateur film of a Loch Lomond holiday and decided filmmaking was for her, making educational films and lecturing with them in schools, she bought a 16mm camera and practised by filming two 50ft rolls in the park. Arriving in Shetland to film seasonal life in January 1931, by autumn had made A Crofter’s Life in Shetland. After cutting the film together she invited John Grierson to view it. He was enthusiastic and advised her on documentary-making techniques and to buy a professional camera, so she bought a 35mm Eyemo.