Doing a little math here:

7:30 AM to 7:30 PM (schoolnights) or 9 PM (weekends) comes out to 86 hours a week, as a starting figure. (out of 168 hours a week).

"It does not go to school with you". Let's assume that to be seven hours a day, transit time included. That brings us down to 41 hours per week.

Turn it off in public: Well, now we're really getting somewhere. Let's assume this kid hangs with friends for an hour each day on schooldays, and spends five hours away from home each day on weekends (mall, friends, whathaveyou.) That brings us down to 26 hours a week.

"Leave your phone home sometimes." Well, that's unsettlingly vague, so we'll just stick with 26 hours. He's graciously allowed to use his Christmas present for a whopping 16% of the time. Isn't she the greatest?

Yes, she can set whatever rules she wants (and obviously does so), but this is not a gift. This is her toy that she lends him. Which she passed off as a major holiday present.