hey guys, I want to get my little sister an iphone 4. She wants a touch but rather than spending more on the touch, att has a refurb Iphone for 100.00. If I add another line so I can get her the iphone how does that work? I have never added a line to my current iphone. She won't be using the phone to call people as she's only like 10, do our minutes become shared or I will have to pay another 100 monthly on my plan?