Born On January 23, 1944, and raised in Dublin, Ireland, Mary Rose Callaghan was educated at the Sacred Heart Convent, a boarding school in Dundrum, from 1953 to 1956; then attended the Sacred Heart Convent in Monkstown until 1959; and finally attended the Loreto Abbey School in Rathfarnham, from which she was graduated in 1962. In 1964 she entered University College, Dublin, and took her baccalaureate degree in 1968. A year later she received her Diploma in Education and taught English and history in secondary schools in England for the next four years.

Although she had always wanted to be a writer, she did not begin writing until she returned to Dublin in 1973 to work on an art magazine. At first she wrote book reviews and art criticism, but in 1975 when she went to America Has Anyone Seen Heather?