Account email change not updating on child's iPhone for app permissions

I recently updated my account information. Specifically, I changed the email address that account was connected to from my work email to my personal email. My childs phone is still using my old email when she requests permission to add an app. Because of this it’s not sending me the permission requests and when I get on their phone it is not accepting my login information when I enter it manually. How do I fix this? Our accounts are connected as family members already.

[Re-Titled by Moderator]

Original Title: Account changes