Her name was Marcella Brooks, but everyone called her “Granny.”

I would see her sitting in her wheelchair in the doorway of a boarded-up Walgreens on Market Street near San Francisco’s Civic Center Plaza, a ragged brown-and-white dog named Missy sprawled across a yellow blanket in her lap. Granny’s eyes would be closed, mouth open a crack. She wore tennis shoes and at least three socks on each foot. Long underwear showed beneath the hem of her dress, and a wool cap covered her gray hair. The handwritten cardboard sign around her neck — Help the Homeless — made passersby pause. A downward tilt at the corners of her mouth even in sleep suggested that Granny disapproved of those who stopped and stared. Some dropped change in a cup by her feet, unaware that she received a thousand dollars a month in Social Security benefits, money she spent renting four storage lockers. Engulfed in a heavy winter coat, Granny looked smaller than she was and gave the impression that at any moment the damp, hard winds rising off the bay might whisk her away.