Is this deportation a result of a mistake on her visa? If not then an attorney when getting the visa would probably have made no difference.
In terms of my individual situation, and thus is my opinion and should not be taken as advise by any other; when filing for my visa to move to America I looked over what needed to be done, with a lot of help off a forum containing guides and lots of wonderful people who have all been through the same situation, and concluded a lawyer at this point was not necessary. If a mistake is made on this visa (K-1, AOS might be a different matter), then they simply tell you, let you correct it and move on. It is a lot of form filling and hoop jumping, however nothing beyond being able to do yourself assuming you can fill a form out and follow some instructions. Weather this is the same for other countries, and other visa's I cannot say.
the one thing that is true, is that it takes a blood long time, and is a whole lot of beaurocracy to sit through. However if your relationship cannot survive a few months apart, with the rest of your life ahead of you, perhaps as delia said, it is not the right time for you to move to the other side of the world.
Regards,
Arch