AppleID

She has to be 13 years old or older for you to set up an Apple ID and not use Family Sharing.

Apple ID - create a new.      *

Apple ID – Create   -

Apple ID - Could Not Create or Could Not Set Up iCloud message.    *

For the error message, some things you can try. Do you have access to another WiFi network where you can try? That has worked for several people.

Try a restart.

Restart your iPhone, iPad, or iPod touch         

Try a forced restart.

Reset Device.      

Try the help in this Apple support article > Create an Apple ID for your child - Apple Support