DC is having an unaluulsy cold and snowy winter; typically the temperatures are in the 40s and L would be fine with my 11 year old's usual attire: her Northface jacket and sneakers, Sambas, or Uggs (probably don't want to mess those up in the slush). We had 6 inches of snow last Saturday, 5 inches last night (snow day today), are forecast to get 6 or more inches this Saturday, and possibly more next Tuesday. I have my fingers crossed that the snow will cease after that. I would keep searching for boots, perhaps even rain boots with a warm lining. Maybe you have time to order them from LL Bean or Land's End. Good luck.