i would like to reset a locked phone...

Follow the steps mentioned in this article to erase the iPhone and set it up again by restoring from the latest backup.

If you forgot your iPhone passcode - Apple Support

If you don't have access to a computer and your iPhone has iOS 15.2 or newer installed, take a look at these steps:

If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support

Hello have you tried plugging it in to your windows or Apple device and restoring your daughters iPhone