A story about adventure on a far - away island. They could talk about how they build a shelter, find food, and make friends with the local inhabitants. This would be an exciting and educational story for the kids, teaching them survival skills and the importance of working together as a family.
A fairy - tale story would be suitable. For instance, a story about a magical forest where the kids get lost and with the help of grandma's wisdom and mom's courage, they find their way back home. It can be full of magical creatures like fairies and talking animals which would be exciting for the kids.
A story about family traditions. Grandma could start by telling how things were done in the old days, like making a special family recipe. Mom could add her own experiences related to that tradition, and the kids could learn about their family heritage. This type of story would strengthen their family bond.