Growing up in northern Vermont near the Canadian border, Johnston developed an early passion for snow laden alpine landscapes and this remains an important theme in her photographic work.

She earned a degree in Art History from Middlebury College in Vermont and was employed by Sotheby's in New York City. In 2001, Johnston began studying photography at The Black and White School of Photography, London, and has since been invited to participate in several group shows. She has had solo exhibitions in London (2006) and Kitzbuhel, Austria (2007-8) and has exhibited at the London Art Fair since 2010.