It was nearly Christmas, and I was out buying the last few bits of plastic for my nieces. Walking along the high street, dodging frantic shoppers and sticky-faced children, I almost fell over the old woman who was sitting on a faded blanket, a grubby terrier curled up next to her. “Spare a penny,” she croaked at me, and while I normally ignore beggars, there was something about this woman, with her rosy cheeks and matted hair, that made me want to help.

I turned on my heel, went into the nearest cafe, came out with two steaming cups of tea and handed one to the woman. “Here,” I said. “I’m Susan. Happy Christmas!”

The woman laughed raucously as she took the tea from me. “Marj,” she said. “Pleased to meet you, I’m sure. Thanks for the tea love, it’s just what I wanted.”

I squatted on the floor next to Marj and for the next half hour we chatted like old friends. I didn’t ask how she’d ended up on the streets, and she didn’t tell me either. Somehow it didn’t seem to matter. But cramp, and my shopping list, got the better of me and eventually I peeled myself off the floor and made to leave. The sky had darkened and rain was impending. “You want to get yourself somewhere warm and dry,” I said, concerned about my new friend.

“Don’t you worry about me,” she said. “I’ll be off to the night shelter in a minute. But here…” She pulled something out of a voluminous bag hidden behind her. “Take my brolly. Looks like rain. Don’t want you getting wet, pet.” I tried to refuse the generous offer, but Marj insisted I take the filthy blue umbrella. In exchange I gave her a ten pound note and my woollen gloves. It seemed like a fair deal.

An hour later and I was at the station waiting for a train home, one hand full of shopping bags and the other clutching the umbrella. As the train approached the station I saw a flash of red run past me towards the tracks. There followed a scream, and I watched as a young boy, no more than three or four, slipped on the edge of the platform and fell onto the tracks. The train was fast approaching and without thinking, I reached out the umbrella to the boy, who grabbed the curled handle and climbed to safety. He ran back to his mother, who hugged him tightly, while I hugged the umbrella to my heart and remembered the kindness of a stranger.