Someone hacked into my girlfriends Icloud and changed her password, now is not able to change it back. The only way she is able to get In is with the Face ID. Can you please tell me how to go about this. We have a good idea who it is. What do we do?

Click on this link "If you think your Apple ID has been compromised" --> https://support.apple.com/HT204145

'Checklist: If you want to see if anyone else has access to your device or accounts' click here --> https://support.apple.com/HT212021

Security and your Apple ID - https://support.apple.com/HT201303

Contact Apple for help with Apple ID account security - https://support.apple.com/HT204169 "This article provides country-specific Apple Support contact information for customers seeking help with their Apple ID password or other security-related issues." Better for directly reporting an issue.