This is the moment an amputee skier carved down a snowy slope—swooping side to side on one leg like an absolute pro. Wendy Gideon, 42, is a congenital amputee, meaning she was born without a leg.

Two years ago on a rainy Friday, an exhausted woman in a bright pink raincoat tried in vain to get a taxi before deciding to get the Tube from her Liverpool Street office. Sarah de Lagarde had worked ...