Her children Isabella, 23, and Connor, 21, were adopted when Kidman was married to US actor Tom Cruise but after their split the children decided to live with their father.
Fr Edward Steiner, from the Roman Catholic Cathedral of the Incarnation in Nashville, told New Idea magazine that "she's definitely praying for those kids".
He said: "The job of parents if to give them a place to land and come back to."
Kidman has previously spoken out saying that her Catholic religion and Tom Cruise's belief in Scientology was a rift between the pair.
Kidman and Cruise adopted Isabella in 1992, and son Connor in 1995.
The couple divorced in 2001.
After the breakup of their 11 year marriage the parents shared custody but the children later then chose to live in Los Angeles with their father.
Both believe in Scientology, and religious differences have created tension between Nicole Kidman and her family, according to a new documentary.
Alex Gibney's film 'Going Clear: Scientology and the Prison of Belief' discusses these relationships, but the Church of Scientology has denied the claims.
Their daughter Isabella got married in 2015 and did not invite her parents.
But a family friend is reported to have told Daily Mail Australia: "There is absolutely no truth in Nicole speaking to a priest about her adopted children.
"She never comments on them."
Speaking in 2013 in Vanity Fair Nicole Kidman said: "I've chosen not to speak publicly about Scientology.
"I have two children who are Scientologists - Connor and Isabella - and I utterly respect their beliefs."
