In terms of post processing, I would (in no particular order):
a) Crop it to nearly square - all that background doesn't contribute anything significant to the image;
b) Move your wife slightly off center - she doesn't have to be positioned exactly by the rule-of-thirds, but you need to do something to break the perfectly centered placement in your original;
c) Brighten up the subjects (ie, as if you had used a bit of fill flash);
d) Warm up the entire photo;
e) Fix the blown sky (upper RH corner);
f) Clean up the smudges on the baby;
g) Adjust the skin color to moderate the lobster red areas.
Unfortunately, the image you supplied is of only moderate resolution, the subjects are slightly soft, and it has other small technical problems which, unfortunately, get magnified in doing the post processing. These will likely be visible to you. When one intends to post process an image, you really need a very, very clean starting image. Because of this, personally, I wouldn't print this any larger than around 5 or 6 inches square, and even that's pushing it.
If you have any questions, don't hesitate to ask.
HTH,
Tom M
