Madonna: Motherhood's a challenge

Despite being the biggest-selling female recording artist in history, Madonna says raising children is as daunting to her as to anyone.

"We all have our challenges," the pop star, 53, told Harry Smith in an interview that aired Wednesday night on NBC's "Rock Center with Brian Williams." "To be a single mother of four and to work as much as I do, [to] live my life in a kind of metaphorical fish bowl, it's pretty challenging. Yeah. But so far I've survived with sanity and humor intact."

To her daughter Lourdes, 15, and son Rocco, 11 -- her children with fitness trainer Carlos Leon and filmmaker Guy Ritchie, respectively -- and her adoptive children, son David and daughter Mercy, both 6, Madonna said she is simply "the one [who] comes home and says, 'Have you done your homework?' and 'Why are you wearing that?' and 'Why did you say that?' and 'What are you eating that for?' "

After Smith noted a much-publicized recent photo of Lourdes caught smoking a cigarette, Madonna conceded, "I wasn't very happy" and admitted that as a parent, "I don't think I'm as tough as I should be. I think I need to be maybe tougher. It's hard, though. It's hard -- every day is a negotiation. But cigarette smoking I'm not very fond of -- for anyone. I don't approve of anyone smoking cigarettes. Most of all my daughter."

In the professional realm, however, in response to Smith asking if she had anything left to prove, she said, "I certainly have stuff left to say. And I think that's really why I'm doing it. I still feel like expressing myself that way. And I'll keep doing it as long as I do."

Newsday reported last week that Madonna has rented out Nassau Coliseum for more than a month for rehearsals, stagecraft and other preparations for her upcoming world tour.