Family share iCloud Storage
I want to share my iCloud Storage with just my wife and not my kids. Is there a way to share iCloud Storage with only specific members of my "Family"?
Sorry, no there is currently no option to do that. You may want to make the suggestion to Apple via: https://www.apple.com/feedback/icloud.html
More information about sharing storage in Share an iCloud storage plan with your family - Apple Support