11/18/2008 AT 08:00 AM EST
admitted she was "reeling" at Tuesday's Sydney premiere of her new epic Australia
– but not from the cameras or crowds.
What had her so stressed? The actress and her husband, Keith Urban
, had to leave 4-month-old daughter Sunday Rose
back home in Nashville – half a world away.
"I had to leave her for 24 hours," Kidman, 41, told reporters at the city's Museum of Contemporary Art. "I haven't done that yet, and so I'm still reeling."
Still, Kidman was together enough to ponder what may be ahead for her.
"In terms of my future as an actor and stuff, I don't know," she said. "I mean, I'm in a place in my life where I've had some great opportunities – but I may just choose to have some more children."
Besides, she said, "There's many things I want to do besides act." And whatever that may be, "I'm very at peace."
For now, though, the Oscar winner said missing the premiere was simply not an option.
"This is a once in a lifetime thing. I mean, rarely do you get to make a film that you've dreamt of making since you were little," said the Australia native. "So when I was flying back with Keith we were so excited. … This is a celebration for me, and hopefully for this country."
Reporting by ANNETTE DASEYWho's your Favorite Star Under 35? PEOPLE.com and the People's Choice Awards are counting your votes! Click here to vote now!RELATED GALLERY:
Nicole & Keith welcome daughter Sunday Rose!