Nicole Kidman admits her four children have an ''interesting dynamic.''

The 'Grace of Monaco' star has daughters Sunday, five, and Faith, three, with husband Keith Urban, and 21-year-old daughter Isabella and 19-year-old son Connor with ex-husband Tom Cruise, but they don't spend a lot of time together.

The 46-year-old actress told The Sunday Times' Style magazine: ''When you have adult children and then tiny little ones, they don't spend much time together. A 21-year-old doesn't have much in common with a three-year-old, but it's an interesting dynamic.''

The Oscar-winning actress, whose youngest daughter was born via surrogate and eldest children were adopted, would love to have another child in the future.

She said: ''I would be down on my knees begging for another one, but that's not going to happen. Even though I got a call from my publicist recently, saying, 'Are you having another baby?' And I said, 'I wish'.''

But Nicole is very happy with her family and says she and Keith still have great ''chemistry.''

She said: ''I have the husband that I'm so grateful to have. I have my soul mate and probably because he's Australian, that has a lot to do with it.

''We were born in the same year [1967], we have all the same references, be it music or just life in general. But I think it's really about chemistry -- you either have chemistry or you don't. And I'm lucky to have it with him... whether it's a common nationality or just pheromones. Whatever it is, it all works.''