Hi, I wanted to get an Ipad for my niece, who will be entering Grade 8 next year. However I'm not sure whether to get a mini or a full sized IPad for her. My objective is to let her use the device as an education tool, since I've heard that the Ipad is highly useful and interactive in explaining content than normal textbook. Although the Ipad mini is lightweight and comfortable for holding over long period of times, I am worried that it can strain the eyes over time. Which one should I choose? Any opinion will be appreciated. Thanks.