[3] In 2004 Twomey won the Margaret George Award, a grant presented by National Archives of Australia to emerging historians, for her "exploration of the experiences of Australian civilians interned by the Japanese in World War II".
[4] Twomey's 2008 book, Australia's Forgotten Prisoners: Civilians Interned by the Japanese in World War Two won a New South Wales Premier's History Award in the John and Patricia Ward History Prize category.
[5] In 2009, the National Archives of Australia awarded Twomey the Frederick Watson Fellowship.
Between 2012 and 2015, she was the co-editor of Australian Historical Studies alongside Catharine Coleborne, after which she was appointed chair of the Board managing that publication.
[7] In 2018, Twomey won the New South Wales Premier's Australian History Prize for her book, The Battle Within: POWs in Postwar Australia.