I've researched and researched and researched some more but I can't seem to find a reliable answer. When I get my 6S, I'm hoping to give my Verizon iPhone 6 to my girlfriend. She is currently using an iPhone 5 on the Sprint Network. Some have said this is possible, others have said it's not. Could she take the SIM card from her iPhone 5 and put it in my iPhone 6? Should she keep the SIM card that's currently in my iPhone 6 and just contact Sprint to do the "bring your own device" thing? Anyone with experience in this arena, please offer up some clarification. I'd love for her to be able to upgrade to my old device once I get my 6S.