I think its more important to know whats the intended use of the laptop
and what kind of portability is expected.
Would you rather have something little bulky, but very powerful or
something light, but powerful enough to take care of
email/browsing and similar light weight processes.
if I had to get one for myself, I'd go with a sub 13in MacBook for its
portability and reliability. But your needs would be different from mine.
She prefers something light, I know that. She wants it for grad school, so something with email/browsing, powerpoint, (which is every computer, I know) and something with a long battery. I'm pretty sure she doesn't do games, or anything that would really need graphics or heavy processing. I'd think she'd want something along the lines of what a business traveler would want.