Wow! What schedules. They are fortunate to have grandparents like you.
Their schedules are incredible.
Even when they were in grade school, their after school schedule was tough.
Once a month we went down to pick up our grandson and ride herd on he and his peers for a hour, until his sister got out. If they had been good kids, we took them to get an ice cream treat. Then drop off to their after school events.
Later fix dinner or buy it for them and their mom. We tried to do this on days our son would be out of town or working late. We did this so our DIL could have a free afternoon.
Over the years, we met grandparents who moved from other cities or states to help with the grandkid activities after school and on weekends.