I agree with tearsplash. I lived in London for a few years and it is important to have a local bank account. They will issue a chip and pin debit card which is also very important to have in the UK. Chip and pin cards are not common in the US yet. Check what deals the school has with local banks and credit unions.
You also want her to have a US card that is linked to yours if she needs to buy flights or make bigger purchases. Make sure the US card does NOT charge foreign fees. Lots of posts on these boards about which are the best of the cards for spending abroad. Good luck. Living abroad is a great experience