If your daughter is trying to switch the Apple ID on her iPhone to her established iCloud email address but is encountering the "email already taken" error, it's important to follow these steps:
1. Sign Out of the Existing Apple ID:
- On the iPhone, go to "Settings."
- Tap on the Apple ID banner at the top.
- Scroll down and choose "Sign Out." This will sign out of the existing Apple ID (associated with the Gmail account).
2. Sign In with iCloud Email:
- After signing out, tap on "Sign In" and enter the iCloud email address and password associated with the family sharing and parental controls.
3. Verify Identity:
- Depending on security settings, she might need to go through two-factor authentication or answer security questions to verify her identity.
4. Complete the Setup:
- Follow the on-screen instructions to complete the setup process. Make sure to choose the appropriate options for family sharing and parental controls during the setup.
If the "email already taken" issue persists, double-check that the iCloud email address is not being used elsewhere or if there are any typos in the email entry. If the problem continues, it's recommended to contact Apple Support for assistance. They can help troubleshoot specific account-related issues and guide you through the process of updating the Apple ID on the device.