The glowing mum-to-be has handed over two of her own pieces of headwear to be sold for the charity DebRA (Dystrophic epidermolysis bullosa Research Association).
Along with her Philip Treacy butterfly hat and her Gabriela Ligenza piece, she showcased some of the 70 or so others going under the virtual hammer, at Bhs Oxford Street, London.
Documentary
Headwear belonging to stars including Ringo Starr, Ewan McGregor, David Jason, Cliff Richard, Emma Thompson and Ian Wright also went on sale yesterday as part of the Celebrity Mad Hatter ebay Auction.
Nell is vice-president of DebRA and befriended Jonny Kennedy, who featured in the documentary The Boy Whose Skin Fell Off, before his death from EB-related cancer in 2003.
The Belle Isle beauty, who is around six months pregnant with her first child, said she had promised Jonny she would support DebRA whenever she could and urged people to raise awareness and funds by bidding for their favourite hat
The ebay auction runs until Sunday, May 21.