The 26-year-old star - who already has a five-month-old daughter Harlow with partner Joel Madden - is said to be expecting her second child, after deciding she wanted a companion for her baby.

A source told America's Star magazine: "Nicole is dying to have a sibling for Harlow who is close in age. She doesn't want them to be more than two years apart, so that they can be best friends forever."

Nicole - who shot to fame when she starred alongside best friend Paris Hilton in MTV reality show 'The Simple Life' - first sparked reports she may soon be adding to her family when she was spotted wearing a flowing lilac 'maternity-style' top.

An onlooker said: "The top was not something Nicole usually wears. She ordinarily goes for tight T-shirts and vest tops. The other unusual thing was that she was wearing comfy sheepskin boots and not her usual heels - the boots definitely looked like something a pregnant woman would wear."

(C) BANG Media International
Photo: WireImage.com

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