From the BBC News:
"A native of County Tipperary, Lt Com O'Brien is currently serving at Irish naval headquarters at Haulbowline.
Her appointment comes four years after a woman was first given command of a ship in the Royal Navy. Lieutenant Charlotte Atkinson assumed command of the HMS Brecon in 2004.
Lt Com O'Brien joined the naval service after leaving school and was one of two female cadets commissioned in 1997. She served as navigator on a 25,000-mile voyage to Asia on the LE Niamh in 2002.
An Irish defence department plan to replace three of the naval service's eight ships, including the Aisling, has been put on hold.
A department spokesperson said the lifespan of the ships would have to be extended."