"The greatest weapon against stress is our ability to choose one thought over another."  —  William James She sat in the open hatch of her ice cream van, parked by the edge of St James’s Park — the kind of London spot where laughter and footsteps blur together in the hum of the city. The day was bright, but she looked as if the light reached her only partially. Her face was thin, the lines around her mouth drawn a little deeper than her years might suggest. She couldn’t have