Hi Nlpkole,
It's not necessary to delete your Apple ID for this purpose, as once an Apple ID is cancelled, t he email used can not be used again for another Apple ID.
Can I use the primary email address for my deleted Apple ID account to create a new Apple ID or with another existing Apple ID account?
No, once your Apple ID is deleted, you can't use the email address that you used with it to create a new Apple ID. In addition, you can't use that email address with another existing Apple ID except as a rescue email. Also, if your primary Apple ID email address is with a Custom Email Domain, it can never be reused to create an Apple ID after your Apple ID is deleted, even if the domain ownership changes.
How to delete your Apple ID account - Apple Support
We'd advise canceling the delete request, and then she can continue to use the Apple ID with restrictions you set from your own device.
If the birthday is incorrect, contact Apple Support if you feel that's necessary, but her Apple ID can be used with her iPhone even if she has a child account. You'll have responsibility for what she can use as the parent on your iCloud family:
Set up Family Sharing
For help sorting out your account concerns, contact Apple Support to be walked through them:
Get Support
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