I noticed today that when my wife gets a call on her iPhone 5S running iOS 8 it also rings on my iPhone 6 Plus running iOS 8. It also happens in the other direction - when I get a call it rings on her phone as well. Checking settings I see that both phones have Handoff turned off. I don't believe that either has family sharing set up ... when I check in settings I see a line which says, "Set Up Family Sharing" ... it's the same on both phones. Is there any way to turn off whatever is causing this?