I think it's top tier US elites (chairman's) that can nominate someone to Silver - no trial required. Some other levels can give some a free trial - I think it's free. Sounds like your wife got the latter.

Either way, unless your planned TATL trip is far enough away that you could wait to sign up for the trial until the changeover date when the status you earn would be good till Feb 2016, sounds like you've got it all lined up.

Jim