Yes it’s really hard work. And exhausting! TV was heavily rationed at home so watching it at mine was a treat. I used to put on YouTube videos of classical concerts. She was mesmerised by all the instruments being played and loved the music. She was 3/4. All too soon that became boring and she wanted American cartoons ( sighs from me ) Other activities included painting with proper watercolour paints on nice paper, they have really vibrant and intense colours , potato prints, cooking, baking, water play in the garden, planting bulbs, washing kitchen doors( her idea), bubbles in the sink, dressing up my tailors dummy with my clothes, finding matching buttons in the button box, on a tray , ( you often see jars of them in charity shops for a couple of pounds) . A good one is timing them and seeing how many times they can jump in a minute or run to the bottom of the garden and back. That uses lots of energy! Pressing flowers and making cards with them. Making water gardens in bowls.. floating leaves and flowers they collect from the garden, filling up bird feeders,etc.
I found if I got engrossed too the time passed more quickly.
I think it’s ok to say grandma is tired and we need to do something quiet for a bit!