At one point, he even debated his wife on the subject on a radio show.
In 1979 O'Connor left her mother and went to live with her father and his new wife.
Since then, while maintaining her singing career, she has occasionally encountered controversy, partly due to her statements and gestures—such as her ordination as a priest despite being a woman with a Roman Catholic background—and her strongly expressed views on organised religion, women's rights, war, and child abuse.
In addition to her ten solo albums, her work includes many singles, songs for films, collaborations with many other artists, and appearances at charity fundraising concerts.
In 1983 her father sent her to Newtown School, an exclusive Quaker boarding school in Waterford, an institution with a much more permissive atmosphere than Grianan.
With the help and encouragement of her Irish language teacher, Joseph Falvey, she recorded a four-song demo, with two covers and two of her own songs which later appeared on her first album.
O'Ceallaigh, who had been fired by U2 for complaining about them in an interview, was outspoken with his views on music and politics, and O'Connor adopted the same habits; she defended the actions of the Provisional IRA and said U2's music was "bombastic". She was paired with veteran producer Mick Glossop, whom she later publicly derided.
They had differing visions regarding her debut album and four months'-worth of recordings were scrapped.
O'Connor in June 1993 wrote a public letter in The Irish Times which asked people to "stop hurting" her: "If only I can fight off the voices of my parents / and gather a sense of self-esteem / Then I'll be able to REALLY sing ..." The letter repeated accusations of abuse by her parents as a child which O'Connor had made in interviews.
Her brother Joseph defended their father to the newspaper but agreed regarding their mother's "extreme and violent abuse, both emotional and physical". I for one am in agony." O'Connor's time as singer for Ton Ton Macoute brought her to the attention of the music industry, and she was eventually signed by Ensign Records.
During this time she became pregnant by her session drummer John Reynolds (who went on to drum with the band Transvision Vamp).