IPhone AppledID change
My spouse has an IPhone that had been set up under my AppleID with my IPhone as the primary. I bought her an IPad, and wanted to link this specifically to her phone for texts, etc. Using my AppleID for this new Ipad created havoc and was altering the ID on my phone, her phone, etc. I decided to set up her IPad under her AppleID which we found she already had. The IPad is now set-up and running with her Apple ID, but I cannot link it to her IPhone number because that is under my AppledID. When I go to change her phone to her AppleID, it states that this E-mail is already taken (presumably because it was set up on the IPad). How do I change her Iphone to her own AppleID.
We can set up family sharing between the AppleIDs and from what I have read this is the best way to go, to keep her devices and my devices separate but connected.
Thanks for any feedback on this.
iPhone 8