It's best to contact the school first to see if there's any specific OS that they'd prefer. There may be utilities that are centric to the curriculum that require a specific type of laptop.
In general, Leo says that portability is important. Tablets are great for that, but the problem is that it isn't great for content creation, such as writing papers. So Leo recommends either a MacBook Air or a Windows based Ultrabook. They're light, powerful, and cost less than a $1,000.
Leo likes the Asus Zenbook for Windows. The Samsung 9 Series is gorgeous. She doesn't really need the most powerful chip either. An i5 will save her some money that she can use to boost her RAM. The Lenovo IdeaPad is a good option if you're looking for a desktop replacement.