|Cruise and Kidman before their divorce. Photo by Terry McGinnis|
A source told Us Weekly magazine: "Nicole told Katie her life is great now and she has no regrets."
Katie, 33, ended her five-year marriage to Tom Cruise, 50, in June and moved to New York City with the couple's six-year-old daughter Suri.
In the weeks leading up to her decision, the brunette beauty had reportedly been confiding in Nicole, 45, about her plans and the Oscar winner offered her support and advice.
The pair became friends shortly after Katie's wedding to Tom in November 2006 and bonded over Nicole and Tom's adopted children, Isabella, 19, and Connor, 17, who lived with their father and Katie.
The source said: "They spoke when Nicole called the kids. She knows what it's like in that house."
Katie and Tom finalised a divorce settlement on July 9, less than two weeks after they split.
In the deal it is believed Katie Holmeswill get primary custody of Suri and will continue to live with her daughter in New York City, with Tom allowed substantial visitation rights. The 'Rock of Ages' star is believed to have agreed to pay $10 million in child support over the next 12 years.
After divorcing Tom, Nicole went on to marry country singer Keith Urban in 2006 and the couple have two daughters Sunday, four, and 17-month-old Faith Margaret.