Kate Moss' baby bash

Dec 4, 2008, 9:30 GMT

British model Kate Moss arrives with children at the switching on of the Christmas lights at the shop of British fashion designer and daughter of Beatles front-man Paul McCartney, Stella McCartney, near London\'s famous Bond Street, Britain, 24 November 2008. EPA/DANIEL DEME

Kate Moss is reportedly throwing a party to announce she is pregnant.

The supermodel - who already has a six-year-old daughter Lila Grace with ex-boyfriend Jefferson Hack - is said to be planning to reveal her happy news at her Cotswolds country home on December 18.

It is believed she will gather all her close friends and family together to tell them she and partner Jamie Hince are having their first child together.

A source said: "Kate has been on the phone to all her friends and her PA has been on the case to her family. Kate has had a few big nights out recently but she has been behaving more than usual. Even Simon Cowell said she had a bit of a tummy when she went to 'The X Factor' last weekend."

Kate, 34, first sparked pregnancy rumours after wearing a series of baggy outfits and cutting alcohol out of her lifestyle.

Meanwhile, it has been revealed Kate took her 60-year-old nanny Mary Davidson on a massive shopping spree at British high street store Topshop.

A source revealed: "Mary was shy and bewildered at first but soon got into the swing as Kate encouraged her. She came away with more than £3,000 of clothes and shoppers found their jaws dropping as they bumped into Kate and she was shouting, 'Come on girl, buy buy buy!' Mary just kept saying, 'But what will I get you for Christmas?' "

However, the bill for the spree was not picked up Kate - who is a designer for the clothing chain - but by Topshop owner Sir Philip Green.