Update grandchild row when child record is updated from parent

Hello:

I have another question for you…

I have a parent table (orders) that already update his child record (order details) when the status is changed.

What i want to achieve is to update a grandchild row (inventory_update) to change existing rows (added when the child row is created) and set update column (Y/N) to Y, when the parent status column is set to “delivered”

Thanks and regards,