In 1767 she fell in love with Captain Art Ó Laoghaire of Rathleigh, Macroom, County Cork. He had recently returned from service in the Hungarian Hussars. Eileen was 23; she had been married to "old O'Connor of Firies" when she was 15, and widowed within six months of that marriage. With the marriage against the express wishes of her family, Art and Eibhlín eloped, marrying on 19 December 1767 and settled down to life at Rathleigh where they lived with Art's father, Conchubhar Ó Laoghaire, having five children, three of whom died in infancy. She was pregnant at the time of Art's death.