I have been a member of
britishexpats.com for years, and found that website very helpful. We plan on moving back to the US, and it helps to get a general idea about possible aggravations/difficulties my husband may face.
She can create an account, go into the USA section and ask her state specific license question and hopefully a Brit in that particular state will chime in. Also, if you're planning on moving within a year, you can gradually build up familiar contacts for her in the area.
A while ago I read there some states "force" you to relinquish your UK license for an American one. The general rule is you're not supposed to carry more than two state licenses, but the DMV isn't prepared to deal with an international license situation.
Please clarify on BE, but the usual suggestion when asked if you're already a license holder is to just say no.
HTH
Laura