She has published four books of poetry – Bar Talk, Trapping a Ghost, In Sight of Home and Her Father's Daughter. Novelist Joseph O'Connor described In Sight of Home as 'a moving, powerful and richly pleasurable read, audaciously imagined and achieved' whilst poet Tess Gallagher said of Her Father's Daughter that 'words are her witching sticks and she employs them with beautiful, engaging intent, the better to make present what has preceded and what approaches.' O'Mahony won the National Women's Poetry Competition in 1997 and was shortlisted for the Patrick Kavanagh Prize and Hennessy Literature Awards.