automation update request - parent & child rows help?


So I have a list of tasks with parent an child rows, see below example of 1 task with 5 children:

I want to make an automation to send an update reminder prior to the due date I do not want it to send individual emails for the parent and child rows I just want it to send an update on the parent rows with child rows included in the update... (too much email spam to same person otherwise)

I have no problem making an update form automation for parent rows or child rows as individual rows but not as a group??

Ideas welcomed