Hi, Havard1969.
We appreciate you taking the time to post in the Apple Support Communities.
If we understand correctly, you’re attempting to log into her Supercell ID in Hay Day, and you’re getting a notice that a verification code is being send to your iCloud email address. It sounds like you aren’t seeing the verification email, so let’s see if we can determine why.
First, if you haven’t already, you may need to check your junk mail filter.
Identify and filter junk mail in iCloud - Apple Support
If you aren’t seeing it in your junk mail or spam folder, make sure that your iCloud email address is the one that was used to create the Supercell ID to which her account is attached.
Hopefully this all helps. If not, you may need to reach out to Supercell on the Hay Day Support page for more in depth assistance:
Help with Verification Codes | Supercell Support Portal
Warmest Regards.