I have a friend who is in her seventies. Despite her age she is an avid Apple fan but made the mistake some time ago of establishing a second Apple ID. Now she has a problem syncing calendars and contacts across her iPhone, iPad and desktop.

Here is the issue;

IdentA is on the iPhone as are 600+ contacts.
IdentB is on the iPad and, because of the email address is the one she wants to use going forward.

My question is this: If I insert IdentB into the iPhone will iCloud then sync the 600 contacts across all three devices?? Is there any danger that she'd lose the 600 contacts??

I'm asking because she needs to access the contacts on the iPad but is terrified of losing the 600 contacts - and I really don't want to give her bad advice.

Have I explained this properly? (I really wish Apple would come up with a way to merge Apple Ids)