UK Nurse looking to return to work in US... help!

Hey everyone-

I found this forum by looking around the web and thought it would be a great place to get some help. My mum studied nursing in England for quite sometime and had to quit nursing to raise my siblings and I. My question for everyone is, if my mum wants to get back into nursing here in the US, what path should she take? If she was previously registered as a nurse in a different country, can she take some sort of refresher course, or must she start from scratch?

Any help would be greatly appreciated, thanks!

-Ben