In case you have mistakenly added the parent's Apple ID credentials and selected the parent's device you can delete the old one and re-enter the new one.
Log in to the control panel first https://www.familyorbit.com/cp
Click on the View button in the "Apple Device Status" section
In the new page that loads, you can press the DELETE [X] button to delete the device added by mistake.
Once done click on the Add New Device to proceed to add the new Apple ID.
Click here to learn how to add a new iOS device using the Apple ID credentials.