Dana was born Rosemary Brown in London in 1951, the fifth of seven children (a sister died at the age of 18 months). Her father, a barber, was also a trumpeter in a dance band, her mother was a pianist in the same band, and all her siblings played an instrument or sang, or both, and retain an involvement with the music industry to this day.
The family returned to their home town of Derry when she was a child. In the 1960s, she and her sister Susan sang duets but their budding joint career was cut short by Susan's marriage.
At 15 Rosemary came second in a talent contest, which resulted in a recording contract. In 1969, she came second in the National Song Contest.
She was an A-level student, planning to train as a teacher of music and English, when she won the 1970 Eurovision Song Contest. That put an end to her academic career. Dana had several hits and in 1979 was voted top female entertainer of the year in Britain.
In 1976 she had a non-malignant growth removed from her vocal cords, raising questions about her future as a singer. She was going out with Damien Scallon, a Newry hotelier, at the time. He was deeply involved in the charismatic movement, and through him she also embraced this more personal and emotional expression of religious faith. In 1978 they married.
After his hotel was bombed for the sixth time, part of the then IRA strategy of bombing economic targets, they moved to Dublin, where they lived for two years.
He trained and worked as an addiction counsellor, and also began to manage her singing career. Its demands competed with those of her family throughout the next decade, as she had four children while continuing to sing, especially in pantomime and summer season work.
Together she and Mr Scallon wrote the song Totus Tuus for the Pope. It shot to number one in the Irish charts. She was approached by a US-based religious recording company, Hope, with which she signed a contract.
In 1984 she accepted an invitation to attend an anti-abortion conference in Kansas city, and began a continuing association with the Society for the Protection of Unborn Children.
In 1990 Mr Scallon was approached by EWTN, the Eternal Word Television Network in Birmingham, Alabama, founded by the conservative Catholic nun, Sister Angelica, to become its director of pilgrimages. He accepted, and the family moved to Alabama.
In 1992 Dana also started to work with the station, singing and presenting a bi-weekly programme, Say Yes. She also continued to sing at rallies and concerts, and her performances became a regular highlight of papal visits to the US.
She made frequent trips back to Ireland and to the UK. In 1993, accompanied by her brother, Gerry, she sang at the annual prayer weekend at Knock, where she also led the Rosary. In 1995 she celebrated 25 years in show-business (this was dated from her Eurovision success) with a video for RTE.
Meanwhile, Mr Scallon had helped found Heartbeat Records, which now produces her records and videos. It is described as "an independent international record and video company concentrating on quality releases for and from the Catholic market".
Last year Mr Scallon quit EWTN and is again concentrating on managing his wife's career. Her programmes on the station have been suspended for the duration of the election campaign.
Campaigning with Dana, one is reminded of the affinity between entertainment and politics. Both require communication skills, a readiness to be constantly open to the demands of the public and an almost permanent inclination to perform.
It is no accident, therefore, that the world of entertainment has produced politicians, famously Ronald Reagan but also, in this State people like Ted Nealon and presidential candidates Mary McAleese and Mary Banotti, who first came into the public eye as television presenters.
On the campaign trail, Dana is the consummate professional, with an almost uncanny ability to gauge her audience.
There was some scepticism initially at her claim that her family would run her campaign. In fact, this is all of a piece with her musical career and the financial as well as blood relationships within this close-knit family.
Her husband, brother John and sister Susan work for her record company, and are now all involved in the campaign, as is another sister, Eileen. Another brother, Gerald, sometimes sings with her and accompanies her on the keyboard. A singer with a band, he is her driver at the moment.
An older brother, Robert, also a musician, has recently suffered a heart attack but otherwise would undoubtedly be involved. Even her 79-year-old mother, Sheila, has been well-prepared for the campaign trail by her years on the road.