It's surprisingly hard to find leads over sixty who aren't just wise mentors or comic relief. But they're out there. Fredrik Backman's 'A Man Called Ove' is an obvious pick for a reason—that stubborn, grieving widower arc feels deeply true to a certain kind of older person, and his gradual reconnection is paced without being saccharine. What I loved more, though, was 'The Thursday Murder Club' by Richard Osman. Joyce, Elizabeth, Ron, and Ibrahim are all retirees in a posh village, but they're sharp, bored, and meddling in cold cases. It's less about being 'inspiring' in a grand way and more about showing cleverness and agency never really retire. They have aches and pains and forget names, but the plot hinges on their collective life experience.
For something quieter, I'd suggest 'The Unlikely Pilgrimage of Harold Fry'. An ordinary, retired man gets a letter and decides to walk across England to see an old friend. It's slow and internal, focusing on regret and the small epiphanies you have when you're alone with the road for miles. Grandma might see a different kind of inspiration there—not achievement, but the quiet courage to reflect and make amends, even if your body protests. I sometimes worry books with older leads treat them like children, but these let them be fully adult, with all the complicated history that implies.