iTunes device backup under Family Sharing
I have set up Family sharing (2 child accounts, each tied to one device). My problem is backing up one of the child devices. When iTunes under my account attempts to transfer purchases that were acquired by this "child ID", with parent approval to buy, iTunes reports that "items could not be transferred to your iTunes library because you are not authorized for them on this computer". Therefore I cannot make a complete backup of the device.
iPhone 4, iOS 7.1.2