How to use a different Apple ID
My daughter’s appleID is default on my phone. How do I change it to my own appleID?
iPhone 12 Pro Max
The best way is to Factory Reset the phone and then set it up as new with your Apple ID. If you simply log out of her Apple ID and log in with yours, you will have problems when the apps on the phone need updating as it will require her password. You may also run into an Activation Lock issue if her information has not been completely removed.
How to factory reset your iPhone, iPad, or iPod touch - Apple Support