Hi Lou, that was so sad to read. Kids can be the nastiest little bu!&$"* can't they? My nine year old already asks when she can shave her legs!!!! And she is fair skinned and haired....just a sign of the times I suppose....sigh....
I don't really know what to suggest, just felt I had to say something. There are probably 'lightening' kits available, but in the long term, it's not really the answer is it? Maybe go to a local salon and ask for their advice [just advice...not treatment....tooooo exspensive!] I know when I was younger my Dad refused to let me shave my legs so I used those sand papery disc things....not ideal, but maybe an alternative!
Aside from that just keep being the Mummy that you are...just keep telling her how beautiful she is.
Lisa x