BEIJING, Jan. 2 -- She is a pin-up for size zero wannabees everywhere, but Simple Life star Nicole Richie, showed off an impressive baby bump out and about in Hollywood Tuesday.

Nicole Richie is engaged to rock star Joel Madden (Photo; China Daily/Agencies) Photo Gallery>>>

    Wearing a stretchy grey sweater and sensible flats, Nicole was accompanied by her fiance, Good Charlotte frontman Joel Madden.

    Well-wishers will be relieved to see the 26-year-old daughter of singer Lionel Richie has put on weight for her pregnancy. The troubled star had suffered a slide into drugs and driving related offences last year, which saw her spend a short time in prison.

    Nicole recently revealed her baby had saved her life.

    "I owe this baby everything and I have a responsibility now," she told Diane Sawyer on ABC News.

    　The socialite admitted she could not believe she was pregnant at first. She told Access Hollywood: "I didn't believe it. I was in shock. I took about 5 different tests!"

    Richie and her betrothed are now eagerly awaiting their new arrival in January.

    But it seems wedding bells will not be ringing any time soon.

    The parents-to-be have been busy preparing for their baby and spreading some good will during the festive season.

    The couple treated 200 needy children to an early Christmas with a party thrown by their newly established charity, The Richie Madden Children's Foundation.

    "We really wanted to give these kids a really wonderful and special Christmas. It's our favorite holiday," said a pregnant Richie.