You mention her doing art and design, so really it's got to be a Mac. In all my years working in the design industry I've never walked into a design studio populated by PCs. For instance our studio has six 27" iMacs, five Mac Pros, and seven MacBook Pros of various sizes! You might have to dig a bit deeper (possibly look for a refurbished model), but it will last, and it will give her a good start later down the line when she's entering the workplace.