Custom Fields in Child Tickets

I have a question about the custom fields and how that data flows between child tickets and the parent ticket. Does anyone have a method where information that is populated inside of the child ticket also populates in the parent ticket?

We have as a part of our onboarding process to create the following steps.

1. Create AD accounts
2. Create ERP accounts
3. Create E-Time accounts
4. Create O365 Accounts
5. Order/Image/Install computer hardware
6. Create Phone system accounts
7. Order Cell Phone
8. Order business cards
9. Configure building access
10. Setup workstation
11. Notify people of new employee information - Just a notification and not a ticket.

For the Order business card step I need information that is documented in multiple tickets to be populated in that ticket so we can effectively order the proper cards. I then also need a notification that will provide that information to the people needed in the last step. I am running the notification off the parent ticket and all of the other tickets are from child tickets. The data is not flowing between them. Is there a step I am missing or does someone have a best practice that will help us make this work?