Mari ni Connal was a female Human Starfleet petty officer first class in the 24th century. Her family came from the same county in Ireland as Miles O'Brien's family did in the 23rd century. Before becoming an enlisted member of Starfleet, she taught aerobics on the USS Enterprise-D.
Ni Connal served on Deep Space 9, where O'Brien considered her almost kin. She maintained some old traditions, like her Catholic faith and identifying people from England as Sacsanachs. O'Brien thought everyone else had abandoned such things two hundred years previously. (DS9 novel: Fallen Heroes)