I have an individual acct with unlimited data. My gf was on a family acct and just assumed liability of her line and was moved to a month-to-month plan. She is due for an upgrade and is not currently a smartphone user. Is there any advantage if I were to add her line to my plan? As I understand, we couldn't really share anything unless I decided to forego my unlimited plan and move to a share anything with her. Would it be best to just keep two separate accounts?