I try to stay out of discussions unless I can contribute something, but since no one has mentioned it, I will.
When I was practicing law I did a fair amount of divorce work. It made me a big fan of mental health counseling. Whether a woman get an augmentation or a reduction, my advice is the same: First, go see a counselor for at least several sessions. The surgery will change her, and that will change the relationship. Many plastic surgeons make the same recommendation, because there are some questions that must be answered by the woman to herself: What is she really looking for? Can the surgery provide it? And a lot more.
Among the divorces that I've done was a very petite, flat-chested woman whose husband wanted her to get an augmentation; she went from a 30B to a 30G. Hubby was really happy until he noticed that every guy they met was way more interested in her than in him. Likewise, she suddenly wasn't a wallflower any more, and a lot of guys who were a lot more interesting than her husband were wanting to spend time with her, and they did.
I've seen the opposite happen, as well. I had a client who worked as a stripper. She had a great set of natural F-cups. If I were to see her again, I would tell her about Lindsey Dawn McKensie, because after she had the reduction to a C-cup, she couldn't get a job.
I'm sure your wife is different, but this really is an important decision.