By removing your child's device from Jamf Parent, you will no longer be able to manage their school-issued device.
To remove a child's device from Jamf Parent, tap the settings button in the upper-right corner, then under Account, locate the name of the child's device you want to remove and tap Remove. When prompted to confirm the removal, tap Yes.
Important:
Tapping Remove will remove all your paired child devices that are registered to the same school from Jamf Parent, not just the selected child device.