Been there -- we had three miscarriages before things worked out. Our first was on vacation too, happened on the plane to Florida, so I can relate. There are two approaches; neither is right or wrong, but as a guy, you can rest assured whichever you pick will be wrong... ;-)
The first is to sit down and try to talk through it. Pro: it may get things out in the open. Con: she may insist nothing is wrong and you're in a seriously awkward position. If it works out, you can push for the "get back in the saddle again" angle and show that you're interested by researching possible causes, such as progesterone deficiency (turned out to be the problem for us) or other potential factors. Otherwise you'll have to backpedal quickly and not push it -- see option #2.
The other approach is to be supportive but hands-off -- similar to what you seem to have done so far. In many cases, this will work, but it could be that your wife's constant references to the miscarriage is a hint that she WANTS you to get more involved. On the other hand, it could be just her needing a lot of time to deal with. Or perhaps it's a little of everything, and she doesn't know quite what she wants either. The female mind is a mystery, and a female mind beset by loss coupled with powerful hormones and motherly instincts is like trying to comprehend quantum physics explained in Korean.
Bottom line: don't overthink it -- accept that you're way out of your league and just try your best. Being there is half the game, and try to pick up on the clues as you go along. That's all you can do, so try and do it well. The only real, definite cure is probably the birth of a healthy baby, so keep that as the long-term goal and keep nudging in that direction as you progess.