Q: After adding new icloud email addresses for 2 new phones for my kids, the devices no longer show on my Find iphone app

My family of 4 has been sharing an icloud. My twins received new iphone 6 upgrades recently. After setting them up some of our calls were being crossed on different devices. So after contacting Apple support, I was instructed to create new icloud email addresses for their devices. Now neither phone shows up in my find iphone app. One has disappeared, and one always shows as offline.....