Depends what she wants to do with it tbh. Most recent Macbooks have very little in the way of upgradable parts so the spec you buy is the one you are stuck with. If you want to run Office and the current MacOS then I think you need 8GB ram. You can probably get away with a 128GB SSD but 256GB would be better. Then it is really whether you can get an i7 or i5 based CPU. I managed to pick up a Macbook Air on here recently at a decent price with i7/8GB/256GB for my son for his Uni work and it does all he needs for writing up coursework and being very portable perfectly.