Side by side, four young cousins chat with their grandmother via a video link. “What’s your favourite sport?” one of them asks Marina Smith as she reclines in a comfy armchair in her Nottinghamshire home. “It used to be tennis and hockey and I am also very interested in horse-jumping,” the 87-year-old replies, before adding: “But I don’t ride a horse!” The response elicits a chuckle from her grandchildren who continue to talk about her likes and dislikes, as well as enquiring what it’s like to be a grandparent. An everyday scene, in other words. Except for one fact. Several...