How much would you be paying for any of those 3 laptops?
I'm willing to bet that none of them make financial sense.
As a student nurse, you're not made of money.
Offer £225 for this fully working, good condition, used premium business laptop:
HP 845 G7 on ebayOr, for something smaller, lighter and cheaper, at the expense of a smaller screen there's this spiffing laptop for £185:
HP 835 G7Go for the 13.3" laptop if you'll be walking round or on the bus or on the train a lot with it and you're towards the slim end of the build spectrum.
Go for the 14" if you're of medium build, or only moderate walking, bus train carrying of the laptop.
Go for a 15.6" or 16" if you have a gym honed body or minimal walking, bus train with the laptop.
For your needs these HP laptops will be lightning fast. They will run all the software you need for your course fine. They will be nice to own and use, thanks to the really well engineered aluminium construction, good quality keyboard, screen, trackpad.