Example: I add my sister as a new line to my Mobile Share Value Plan and she gets the new iPhone 6+ through "Next." Later she decides she would rather have my iPhone 5S, so we swap sims/phones. Will the "Next" financed phone still be tied to her number/line (the line on which the iPhone 6+ was originally purchased/activated), even though she would now be using my 5S? Or does the Next financing "transfer" over to MY number/line once the sims are swapped? Thanks!