Kearns has worked in communication roles at the Ministry of Defence (MOD), Ministry of Justice (MoJ), and the Foreign and Commonwealth Office (FCO). She was the lead press officer for MOD's contribution to the 2014 Scottish independence referendum campaign, and the government's communication campaigns in Syria and Iraq for the FCO. At the MoJ, she worked as the Victims' Minister's press secretary. Kearns became the client services director for the strategic communications consultancy Global Influence in 2016. She later became an independent consultant.