I guess I'm not stating things well frown

Ok We have been using this Apple ID with iTunes for purchases for years....that is all it is used for. When she got an iphone for Christmas, I set the phone up using this ID, I should have only put the ID in the iTunes store part of the phone so she could get to our music, but I didn't, I put in the iCloud section also of the iPhone.
Now she has her own Macbook Pro and she created an iCloud account of her own and now I need to put that on her iPhone, but the only way I can see to do that is to "Delete Account" option on her iPhone to get the one we are using for iTunes off.

Does that make sense?