(pr-inside.com) - Spice Girl Melanie Brown has contributed to the girl power cause - by posing naked for a charity campaigning against sex trafficking.The singer can be seen baring all in a new campaign for the Helen Bamber Foundation, a British human rights organisation benefiting survivors of the sex slave trade.She says, "I'm curvier now I've had kids but I like the way I look. Women's bodies are beautiful and any charity helping women is important."