Kidman adopted Isabella, now 26, and Connor, now 24, with Cruise.
Kidman grew apart from them when they followed Cruise into the Church of Scientology. She is now trying to heal the rift.
"Motherhood is about the journey. There are going to be incredible peaks and valleys, whether you are an adopting mother or a birth mother. What a child needs is love.
They have made choices to be Scientologists. It's our job as a parent to always offer unconditional love," Kidman said in an interview to The Sun.
It was rumoured that the relationship between the actor and her children was so strained that she was banned from attending Connor's wedding to Silvia, who is the leader of the Italian arm of the Scientology church.
In fact, she has little contact with Isabella, who is married and living in Croydon, South London.
Kidman, who also has two daughters with her second husband and musician Keith Urban, believes she has come to terms with her their lives. "It's not about anything else other than, 'I'm here to love and support you'," said the 52-year-old.