Barnard graduated with a BA in Photography from the University of Brighton in 2005. She gained an MA in Photography with Critical Theory.

In the group exhibition Theatres of War, curated by Mark Power in 2007, "Barnard documented the tragically tacky 'care packages' dispatched to American troops stationed abroad". Peter Conrad, reviewing the exhibition in The Guardian explained Barnard's photographs by asking "how can Soldiers who ask their families to send them Beanie Babies and whoopee cushions hope to understand the gangs of Islamic insurgents they are fighting?".

Her first book, Chateau Despair, explores the disused Conservative Campaign Headquarters of the UK Conservative Party at 32 Smith Square, Westminster, London – nicknamed Chateau Despair, the scene of many televised historic moments in Conservative history from Margaret Thatcher's victory rallies to Iain Duncan Smith's resignation. "Barnard's images speak of the fleeting nature of political power and the often makeshift working environments that lurk beyond the gaze of the TV camera or the official portrait." Chateau Despair was included in critic Sean O'Hagan's list of "The best independent photobooks of 2013" in The Guardian and New Statesman made it their Picture Book Of The Week.

Barnard was senior lecturer on documentary photography at University of South Wales, then a reader in photography there from 2017.

Barnard’s "complicated and intriguing multimedia project" Virtual Iraq "examines the use of interactive media by the US army to recruit, train and treat military personnel before and after they embark on a tour of duty to the Middle East. It [ . . . ] explores the relationship between the US army, virtual reality and the Gaming industry" in their Flatworld project. Barnard filmed it at the Institute for Creative Technologies, "a research centre also funded by the military to create training applications using virtual reality in advanced technologies." Gordon MacDonald, reviewing Virtual Iraq in Photoworks Biannual, said "Barnard’s project does not aim to direct you towards the ridiculous aspects of Flatworld or to point out the serious moral questions its existence raises. It achieves more than this by simply removing Flatworld from its context and holding all of its contradictions still to be viewed."