It's a decision that reportedly drove a wedge between the kids and Nicole - the Moulin Rouge! star hasn't been pictured with her adopted offspring in over a decade and continues to fail to mention them at key public events. They have made choices to be Scientologists and as a mother, it's my job to love them.
Following a wave of criticism from fans, Nicole made a conscious effort to address Bella and Connor at the Critics" Choice Awards in January as she picked up her gong for her role in Big Little Lies, saying: "I want to thank all of my children who show me so much love'.
Over the years, there has been speculation that the siblings have become estranged from their mother, and more so when she married Keith Urban in 2006 and had two biological children, Sunday, 10, and Faith, 7. "I have to protect all those relationships" she explained.
And the 51-year-old doubled down on those claims on Thursday, telling Australia's World Health Organization magazine: 'I don't know why the culture is set up like that and we aren't just protected anyway, but it's interesting that the power of another man gives you respect'. I love her a lot.
It comes after former Scientologist Leah Remini published a controversial book Troublemaker: Surviving Hollywood and Scientology, claiming Nicole may have been made an "SP" by the church. This was never confirmed at the time, and the Church of Scientology reportedly denied it. Her career is still going, and she has a husband and family ...
Meanwhile, it comes after Isabella paid a surprise tribute to her mother earlier this year when she acknowledged her surname in her new fashion line, labelling it BKC - which stands for Bella Kidman Cruise. "This movie is a love letter to my children", she told Town & Country magazine.
'I think when you're married to a very powerful male - I mean, I'm not in a male's mind - but would you?' she said.
This year Kidman has been uncharacteristically open about her "past life" with Cruise in several interviews - just last month she described herself as being "cocooned" during their marriage. "So when I came out of it at 32, 33, it's nearly like I had to grow up".